/*
 * @(#)HTTPConnection.java   0.3-3 06/05/2001
 *
 *  This file is part of the HTTPClient package
 *  Copyright (C) 1996-2001 Ronald Tschal�r
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free
 *  Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 *  MA 02111-1307, USA
 *
 *  For questions, suggestions, bug-reports, enhancement-requests etc.
 *  I may be contacted at:
 *
 *  ronald@innovation.ch
 *
 *  The HTTPClient's home page is located at:
 *
 *  http://www.innovation.ch/java/HTTPClient/
 *
 */

package org.everrest.http.client;

import org.everrest.core.util.Logger;

import javax.xml.stream.XMLOutputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;
import java.applet.Applet;
import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.io.OutputStream;
import java.net.ConnectException;
import java.net.InetAddress;
import java.net.NoRouteToHostException;
import java.net.Socket;
import java.net.SocketException;
import java.net.URL;
import java.net.UnknownHostException;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Vector;

/**
 * This class implements http protocol requests; it contains most of HTTP/1.1
 * and ought to be unconditionally compliant. Redirections are automatically
 * handled, and authorizations requests are recognized and dealt with via an
 * authorization handler. Only full HTTP/1.0 and HTTP/1.1 requests are
 * generated. HTTP/1.1, HTTP/1.0 and HTTP/0.9 responses are recognized.
 * <p/>
 * Using the HTTPClient should be quite simple. First add the import statement '
 * <code>import HTTPClient.*;</code>' to your file(s). Request can then be sent
 * using one of the methods <var>Head()</var>, <var>Get()</var>,
 * <var>Post()</var>, etc in <var>HTTPConnection</var>. These methods all return
 * an instance of <var>HTTPResponse</var> which has methods for accessing the
 * response headers (<var>getHeader()</var>, <var>getHeaderAsInt()</var>, etc),
 * various response info (<var>getStatusCode()</var>,
 * <var>getReasonLine()</var>, etc) and the reponse data (<var>getData()</var>,
 * <var>getText()</var>, and <var>getInputStream()</var>). Following are some
 * examples.
 * <p/>
 * If this is in an applet you can retrieve files from your server as follows:
 * <p/>
 * <PRE>
 * try
 * {
 * HTTPConnection con = new HTTPConnection(this);
 * HTTPResponse rsp = con.Get(&quot;/my_file&quot;);
 * if (rsp.getStatusCode() &gt;= 300)
 * {
 * System.err.println(&quot;Received Error: &quot; + rsp.getReasonLine());
 * System.err.println(rsp.getText());
 * }
 * else
 * data = rsp.getData();
 * rsp = con.Get(&quot;/another_file&quot;);
 * if (rsp.getStatusCode() &gt;= 300)
 * {
 * System.err.println(&quot;Received Error: &quot; + rsp.getReasonLine());
 * System.err.println(rsp.getText());
 * }
 * else
 * other_data = rsp.getData();
 * }
 * catch (IOException ioe)
 * {
 * System.err.println(ioe.toString());
 * }
 * catch (ModuleException me)
 * {
 * System.err.println(&quot;Error handling request: &quot; + me.getMessage());
 * }
 * </PRE>
 * <p/>
 * This will get the files "/my_file" and "/another_file" and put their contents
 * into byte[]'s accessible via <code>getData()</code>. Note that you need to
 * only create a new <var>HTTPConnection</var> when sending a request to a new
 * server (different host or port); although you may create a new
 * <var>HTTPConnection</var> for every request to the same server this
 * <strong>not</strong> recommended, as various information about the server is
 * cached after the first request (to optimize subsequent requests) and
 * persistent connections are used whenever possible.
 * <p/>
 * To POST form data you would use something like this (assuming you have two
 * fields called <var>name</var> and <var>e-mail</var>, whose contents are
 * stored in the variables <var>name</var> and <var>email</var>):
 * <p/>
 * <PRE>
 * try
 * {
 * NVPair form_data[] = new NVPair[2];
 * form_data[0] = new NVPair(&quot;name&quot;, name);
 * form_data[1] = new NVPair(&quot;e-mail&quot;, email);
 * HTTPConnection con = new HTTPConnection(this);
 * HTTPResponse rsp = con.Post(&quot;/cgi-bin/my_script&quot;, form_data);
 * if (rsp.getStatusCode() &gt;= 300)
 * {
 * System.err.println(&quot;Received Error: &quot; + rsp.getReasonLine());
 * System.err.println(rsp.getText());
 * }
 * else
 * stream = rsp.getInputStream();
 * }
 * catch (IOException ioe)
 * {
 * System.err.println(ioe.toString());
 * }
 * catch (ModuleException me)
 * {
 * System.err.println(&quot;Error handling request: &quot; + me.getMessage());
 * }
 * </PRE>
 * <p/>
 * Here the response data is read at leasure via an <var>InputStream</var>
 * instead of all at once into a <var>byte[]</var>.
 * <p/>
 * As another example, if you have a URL you're trying to send a request to you
 * would do something like the following:
 * <p/>
 * <PRE>
 * try
 * {
 * URL url = new URL(&quot;http://www.mydomain.us/test/my_file&quot;);
 * HTTPConnection con = new HTTPConnection(url);
 * HTTPResponse rsp = con.Put(url.getFile(), &quot;Hello World&quot;);
 * if (rsp.getStatusCode() &gt;= 300)
 * {
 * System.err.println(&quot;Received Error: &quot; + rsp.getReasonLine());
 * System.err.println(rsp.getText());
 * }
 * else
 * text = rsp.getText();
 * }
 * catch (IOException ioe)
 * {
 * System.err.println(ioe.toString());
 * }
 * catch (ModuleException me)
 * {
 * System.err.println(&quot;Error handling request: &quot; + me.getMessage());
 * }
 * </PRE>
 * <p/>
 * There are a whole number of methods for each request type; however the
 * general forms are ([...] means that the enclosed is optional):
 * <ul>
 * <li>Head ( file [, form-data [, headers ] ] )
 * <li>Head ( file [, query [, headers ] ] )
 * <li>Get ( file [, form-data [, headers ] ] )
 * <li>Get ( file [, query [, headers ] ] )
 * <li>Post ( file [, form-data [, headers ] ] )
 * <li>Post ( file [, data [, headers ] ] )
 * <li>Post ( file [, stream [, headers ] ] )
 * <li>Put ( file , data [, headers ] )
 * <li>Put ( file , stream [, headers ] )
 * <li>Delete ( file [, headers ] )
 * <li>Options ( file [, headers [, data] ] )
 * <li>Options ( file [, headers [, stream] ] )
 * <li>Trace ( file [, headers ] )
 * </ul>
 *
 * @author Ronald Tschal�r
 * @version 0.3-3 06/05/2001
 */
public class HTTPConnection implements GlobalConstants, HTTPClientModuleConstants {
    private static final Logger LOG = Logger.getLogger(HTTPConnection.class);

    /** The current version of this package. */
    public final static String version = "RPT-HTTPClient/0.3-3";

    /** The default context */
    private final static Object dflt_context = new Object();

    /** The current context */
    private Object Context = null;

    /** The protocol used on this connection */
    private int Protocol;

    /** The server's protocol version; M.m stored as (M<<16 | m) */
    int ServerProtocolVersion;

    /** Have we gotten the server's protocol version yet? */
    boolean ServProtVersKnown;

    /**
     * The protocol version we send in a request; this is always HTTP/1.1 unless
     * we're talking to a broken server in which case it's HTTP/1.0
     */
    private String RequestProtocolVersion;

    /** The remote host this connection is associated with */
    private String Host;

    /** The remote port this connection is attached to */
    private int Port;

    /** The local address this connection is associated with */
    private InetAddress LocalAddr;

    /** The local port this connection is attached to */
    private int LocalPort;

    /** The current proxy host to use (if any) */
    private String Proxy_Host = null;

    /** The current proxy port */
    private int Proxy_Port;

    /** The default proxy host to use (if any) */
    private static String Default_Proxy_Host = null;

    /** The default proxy port */
    private static int Default_Proxy_Port;

    /** The list of hosts for which no proxy is to be used */
    private static CIHashtable non_proxy_host_list = new CIHashtable();

    private static Vector non_proxy_dom_list = new Vector();

    private static Vector non_proxy_addr_list = new Vector();

    private static Vector non_proxy_mask_list = new Vector();

    /** The socks server to use */
    private SocksClient Socks_client = null;

    /** The default socks server to use */
    private static SocksClient Default_Socks_client = null;

    /** the current stream demultiplexor */
    private StreamDemultiplexor input_demux = null;

    /** a list of active stream demultiplexors */
    LinkedList DemuxList = new LinkedList();

    /** a list of active requests */
    private LinkedList RequestList = new LinkedList();

    /** does the server support keep-alive's? */
    private boolean doesKeepAlive = false;

    /** have we been able to determine the above yet? */
    private boolean keepAliveUnknown = true;

    /** the maximum number of requests over a HTTP/1.0 keep-alive connection */
    private int keepAliveReqMax = -1;

    /** the number of requests over a HTTP/1.0 keep-alive connection left */
    private int keepAliveReqLeft;

    /** hack to force buffering of data instead of using chunked T-E */
    private static boolean no_chunked = false;

    /** hack to force HTTP/1.0 requests */
    private static boolean force_1_0 = false;

    /** hack to be able to disable pipelining */
    private static boolean neverPipeline = false;

    /** hack to be able to disable keep-alives */
    private static boolean noKeepAlives = false;

    /** hack to work around M$ bug */
    private static boolean haveMSLargeWritesBug = false;

    /**
     * hack to only enable defered handling of streamed requests when configured
     * to do so.
     */
    static boolean deferStreamed = false;

    /** the default timeout to use for new connections */
    private static int DefaultTimeout = 0;

    /** the timeout to use for reading responses */
    private int Timeout;

    /** The list of default http headers */
    private NVPair[] DefaultHeaders = new NVPair[0];

    /** The default list of modules (as a Vector of Class objects) */
    private static Vector DefaultModuleList;

    /** The list of modules (as a Vector of Class objects) */
    private Vector ModuleList;

    /** controls whether modules are allowed to interact with user */
    private static boolean defaultAllowUI = true;

    /** controls whether modules are allowed to interact with user */
    private boolean allowUI;

    private static final Logger log = Logger.getLogger(HTTPConnection.class);

    static {
      /*
       * Let's try and see if we can figure out whether any proxies are being
       * used.
       */

        try
        // JDK 1.1 naming
        {
            String host = System.getProperty("http.proxyHost");
            if (host == null)
                throw new Exception(); // try JDK 1.0.x naming
            int port = Integer.getInteger("http.proxyPort", -1).intValue();

            if (log.isDebugEnabled())
                log.debug("using proxy " + host + ":" + port);

            setProxyServer(host, port);
        } catch (Exception e) {
            try
            // JDK 1.0.x naming
            {
                if (Boolean.getBoolean("proxySet")) {
                    String host = System.getProperty("proxyHost");
                    int port = Integer.getInteger("proxyPort", -1).intValue();

                    if (log.isDebugEnabled())
                        log.debug("using proxy " + host + ":" + port);

                    setProxyServer(host, port);
                }
            } catch (Exception ee) {
                Default_Proxy_Host = null;
            }
        }

      /*
       * now check for the non-proxy list
       */
        try {
            String hosts = System.getProperty("HTTPClient.nonProxyHosts");
            if (hosts == null)
                hosts = System.getProperty("http.nonProxyHosts");

            String[] list = Util.splitProperty(hosts);
            dontProxyFor(list);
        } catch (Exception e) {
        }

      /*
       * we can't turn the JDK SOCKS handling off, so we don't use the properties
       * 'socksProxyHost' and 'socksProxyPort'. Instead we define
       * 'HTTPClient.socksHost', 'HTTPClient.socksPort' and
       * 'HTTPClient.socksVersion'.
       */
        try {
            String host = System.getProperty("HTTPClient.socksHost");
            if (host != null && host.length() > 0) {
                int port = Integer.getInteger("HTTPClient.socksPort", -1).intValue();
                int version = Integer.getInteger("HTTPClient.socksVersion", -1).intValue();

                if (log.isDebugEnabled())
                    log.debug("using SOCKS " + host + ":" + port);

                if (version == -1)
                    setSocksServer(host, port);
                else
                    setSocksServer(host, port, version);
            }
        } catch (Exception e) {
            Default_Socks_client = null;
        }

        // Set up module list

        // String modules = "HTTPClient.RetryModule|" +
        // "HTTPClient.CookieModule|" +
        // "HTTPClient.RedirectionModule|" +
        // "HTTPClient.AuthorizationModule|" +
        // "HTTPClient.DefaultModule|" +
        // "HTTPClient.TransferEncodingModule|" +
        // "HTTPClient.ContentMD5Module|" +
        // "HTTPClient.ContentEncodingModule";

        String modules = "org.everrest.http.client.RetryModule|" //
                         + "org.everrest.http.client.CookieModule|" //
                         + "org.everrest.http.client.RedirectionModule|" //
                         + "org.everrest.http.client.AuthorizationModule|" //
                         + "org.everrest.http.client.DefaultModule|" //
                         + "org.everrest.http.client.TransferEncodingModule|" //
                         + "org.everrest.http.client.ContentMD5Module|" //
                         + "org.everrest.http.client.ContentEncodingModule";

        boolean in_applet = false;
        try {
            modules = System.getProperty("HTTPClient.Modules", modules);
        } catch (SecurityException se) {
            in_applet = true;
        }

        DefaultModuleList = new Vector();
        String[] list = Util.splitProperty(modules);
        for (int idx = 0; idx < list.length; idx++) {
            try {
                String mname = list[idx];
                DefaultModuleList.addElement(Class.forName(mname));

                if (log.isDebugEnabled())
                    log.debug("added module " + list[idx]);

            } catch (ClassNotFoundException cnfe) {
                if (!in_applet)
                    throw new NoClassDefFoundError(cnfe.getMessage());

            /*
             * Just ignore it. This allows for example applets to just load the
             * necessary modules - if you don't need a module then don't provide it,
             * and it won't be added to the list. The disadvantage is that if you
             * accidently misstype a module name this will lead to a "silent" error.
             */
            }
        }

      /*
       * Hack: disable pipelining
       */
        try {
            neverPipeline = Boolean.getBoolean("HTTPClient.disable_pipelining");
            if (neverPipeline) {
                if (log.isDebugEnabled())
                    log.debug("disabling pipelining");

            }
        } catch (Exception e) {
            // nothing to do
        }

      /*
       * Hack: disable keep-alives
       */
        try {
            noKeepAlives = Boolean.getBoolean("HTTPClient.disableKeepAlives");
            if (noKeepAlives) {
                if (log.isDebugEnabled())
                    log.debug("disabling keep-alives");

            }
        } catch (Exception e) {
            // notning to do
        }

      /*
       * Hack: force HTTP/1.0 requests
       */
        try {
            force_1_0 = Boolean.getBoolean("HTTPClient.forceHTTP_1.0");
            if (force_1_0) {
                if (log.isDebugEnabled())
                    log.debug("forcing HTTP/1.0 requests");

            }
        } catch (Exception e) {
        }

      /*
       * Hack: prevent chunking of request data
       */
        try {
            no_chunked = Boolean.getBoolean("HTTPClient.dontChunkRequests");
            if (no_chunked) {
                if (log.isDebugEnabled())
                    log.debug("never chunking requests");

            }
        } catch (Exception e) {
        }

      /*
       * M$ bug: large writes hang the stuff
       */
        try {
            if (System.getProperty("os.name").indexOf("Windows") >= 0
                && System.getProperty("java.version").startsWith("1.1"))
                haveMSLargeWritesBug = true;
            if (haveMSLargeWritesBug) {
                if (log.isDebugEnabled())
                    log.debug("splitting large writes into 20K chunks (M$ bug)");

            }
        } catch (Exception e) {
        }

      /*
       * Deferring the handling of responses to requests which used an output
       * stream is new in V0.3-3. Because it can cause memory leaks for apps which
       * aren't expecting this, we only enable this feature if explicitly
       * requested to do so.
       */
        try {
            deferStreamed = Boolean.getBoolean("HTTPClient.deferStreamed");
            if (deferStreamed) {
                if (log.isDebugEnabled())
                    log.debug("enabling defered handling of responses to streamed requests");

            }
        } catch (Exception e) {
        }
    }

    // Constructors

    /**
     * Constructs a connection to the host from where the applet was loaded. Note
     * that current security policies only let applets connect home.
     *
     * @param applet
     *         the current applet
     */
    public HTTPConnection(Applet applet) throws ProtocolNotSuppException {
        this(applet.getCodeBase().getProtocol(), applet.getCodeBase().getHost(), applet.getCodeBase().getPort());
    }

    /**
     * Constructs a connection to the specified host on port 80
     *
     * @param host
     *         the host
     */
    public HTTPConnection(String host) {
        Setup(HTTP, host, 80, null, -1);
    }

    /**
     * Constructs a connection to the specified host on the specified port
     *
     * @param host
     *         the host
     * @param port
     *         the port
     */
    public HTTPConnection(String host, int port) {
        Setup(HTTP, host, port, null, -1);
    }

    /**
     * Constructs a connection to the specified host on the specified port, using
     * the specified protocol (currently only "http" is supported).
     *
     * @param prot
     *         the protocol
     * @param host
     *         the host
     * @param port
     *         the port, or -1 for the default port
     * @throws ProtocolNotSuppException
     *         if the protocol is not HTTP
     */
    public HTTPConnection(String prot, String host, int port) throws ProtocolNotSuppException {
        this(prot, host, port, null, -1);
    }

    /**
     * Constructs a connection to the specified host on the specified port, using
     * the specified protocol (currently only "http" is supported), local
     * address, and local port.
     *
     * @param prot
     *         the protocol
     * @param host
     *         the host
     * @param port
     *         the port, or -1 for the default port
     * @param localAddr
     *         the local address to bind to
     * @param lcoalPort
     *         the local port to bind to
     * @throws ProtocolNotSuppException
     *         if the protocol is not HTTP
     */
    public HTTPConnection(String prot, String host, int port, InetAddress localAddr, int localPort)
            throws ProtocolNotSuppException {
        prot = prot.trim().toLowerCase();

        // if (!prot.equals("http") && !prot.equals("https"))
        if (!prot.equals("http"))
            throw new ProtocolNotSuppException("Unsupported protocol '" + prot + "'");

        if (prot.equals("http"))
            Setup(HTTP, host, port, localAddr, localPort);
        else if (prot.equals("https"))
            Setup(HTTPS, host, port, localAddr, localPort);
        else if (prot.equals("shttp"))
            Setup(SHTTP, host, port, localAddr, localPort);
        else if (prot.equals("http-ng"))
            Setup(HTTP_NG, host, port, localAddr, localPort);
    }

    /**
     * Constructs a connection to the host (port) as given in the url.
     *
     * @param url
     *         the url
     * @throws ProtocolNotSuppException
     *         if the protocol is not HTTP
     */
    public HTTPConnection(URL url) throws ProtocolNotSuppException {
        this(url.getProtocol(), url.getHost(), url.getPort());
    }

    /**
     * Constructs a connection to the host (port) as given in the uri.
     *
     * @param uri
     *         the uri
     * @throws ProtocolNotSuppException
     *         if the protocol is not HTTP
     */
    public HTTPConnection(URI uri) throws ProtocolNotSuppException {
        this(uri.getScheme(), uri.getHost(), uri.getPort());
    }

    /**
     * Sets the class variables. Must not be public.
     *
     * @param prot
     *         the protocol
     * @param host
     *         the host
     * @param port
     *         the port
     * @param localAddr
     *         the local address to bind to; if null, it's ignored
     * @param localPort
     *         the local port to bind to
     */
    private void Setup(int prot, String host, int port, InetAddress localAddr, int localPort) {
        Protocol = prot;
        Host = host.trim().toLowerCase();
        Port = port;
        LocalAddr = localAddr;
        LocalPort = localPort;

        if (Port == -1)
            Port = URI.defaultPort(getProtocol());

        if (Default_Proxy_Host != null && !matchNonProxy(Host))
            setCurrentProxy(Default_Proxy_Host, Default_Proxy_Port);
        else
            setCurrentProxy(null, 0);

        Socks_client = Default_Socks_client;
        Timeout = DefaultTimeout;
        ModuleList = (Vector)DefaultModuleList.clone();
        allowUI = defaultAllowUI;
        if (noKeepAlives)
            setDefaultHeaders(new NVPair[]{new NVPair("Connection", "close")});
    }

    /**
     * Determines if the given host matches any entry in the non-proxy list.
     *
     * @param host
     *         the host to match - must be trim()'d and lowercase
     * @return true if a match is found, false otherwise
     * @see #dontProxyFor(java.lang.String)
     */
    private boolean matchNonProxy(String host) {
        // Check host name list

        if (non_proxy_host_list.get(host) != null)
            return true;

        // Check domain name list

        for (int idx = 0; idx < non_proxy_dom_list.size(); idx++)
            if (host.endsWith((String)non_proxy_dom_list.elementAt(idx)))
                return true;

        // Check IP-address and subnet list

        if (non_proxy_addr_list.size() == 0)
            return false;

        InetAddress[] host_addr;
        try {
            host_addr = InetAddress.getAllByName(host);
        } catch (UnknownHostException uhe) {
            return false;
        } // maybe the proxy has better luck

        for (int idx = 0; idx < non_proxy_addr_list.size(); idx++) {
            byte[] addr = (byte[])non_proxy_addr_list.elementAt(idx);
            byte[] mask = (byte[])non_proxy_mask_list.elementAt(idx);

            ip_loop:
            for (int idx2 = 0; idx2 < host_addr.length; idx2++) {
                byte[] raw_addr = host_addr[idx2].getAddress();
                if (raw_addr.length != addr.length)
                    continue;

                for (int idx3 = 0; idx3 < raw_addr.length; idx3++) {
                    if ((raw_addr[idx3] & mask[idx3]) != (addr[idx3] & mask[idx3]))
                        continue ip_loop;
                }
                return true;
            }
        }

        return false;
    }

    // Methods

    /**
     * Sends the HEAD request. This request is just like the corresponding GET
     * except that it only returns the headers and no data.
     *
     * @param file
     *         the absolute path of the file
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     * @see #Get(java.lang.String)
     */
    public HTTPResponse Head(String file) throws IOException, ModuleException {
        return Head(file, (String)null, null);
    }

    /**
     * Sends the HEAD request. This request is just like the corresponding GET
     * except that it only returns the headers and no data.
     *
     * @param file
     *         the absolute path of the file
     * @param form_data
     *         an array of Name/Value pairs
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     * @see #Get(java.lang.String, HTTPClient.NVPair[])
     */
    public HTTPResponse Head(String file, NVPair form_data[]) throws IOException, ModuleException {
        return Head(file, form_data, null);
    }

    /**
     * Sends the HEAD request. This request is just like the corresponding GET
     * except that it only returns the headers and no data.
     *
     * @param file
     *         the absolute path of the file
     * @param form_data
     *         an array of Name/Value pairs
     * @param headers
     *         additional headers
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     * @see #Get(java.lang.String, HTTPClient.NVPair[], HTTPClient.NVPair[])
     */
    public HTTPResponse Head(String file, NVPair[] form_data, NVPair[] headers) throws IOException, ModuleException {
        String File = stripRef(file), query = Codecs.nv2query(form_data);
        if (query != null && query.length() > 0)
            File += "?" + query;

        return setupRequest("HEAD", File, headers, null, null);
    }

    /**
     * Sends the HEAD request. This request is just like the corresponding GET
     * except that it only returns the headers and no data.
     *
     * @param file
     *         the absolute path of the file
     * @param query
     *         the query string; it will be urlencoded
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     * @see #Get(java.lang.String, java.lang.String)
     */
    public HTTPResponse Head(String file, String query) throws IOException, ModuleException {
        return Head(file, query, null);
    }

    /**
     * Sends the HEAD request. This request is just like the corresponding GET
     * except that it only returns the headers and no data.
     *
     * @param file
     *         the absolute path of the file
     * @param query
     *         the query string; it will be urlencoded
     * @param headers
     *         additional headers
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     * @see #Get(java.lang.String, java.lang.String, HTTPClient.NVPair[])
     */
    public HTTPResponse Head(String file, String query, NVPair[] headers) throws IOException, ModuleException {
        String File = stripRef(file);
        if (query != null && query.length() > 0)
            File += "?" + Codecs.URLEncode(query);

        return setupRequest("HEAD", File, headers, null, null);
    }

    /**
     * GETs the file.
     *
     * @param file
     *         the absolute path of the file
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Get(String file) throws IOException, ModuleException {
        return Get(file, (String)null, null);
    }

    /**
     * GETs the file with a query consisting of the specified form-data. The data
     * is urlencoded, turned into a string of the form
     * "name1=value1&name2=value2" and then sent as a query string.
     *
     * @param file
     *         the absolute path of the file
     * @param form_data
     *         an array of Name/Value pairs
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Get(String file, NVPair form_data[]) throws IOException, ModuleException {
        return Get(file, form_data, null);
    }

    /**
     * GETs the file with a query consisting of the specified form-data. The data
     * is urlencoded, turned into a string of the form
     * "name1=value1&name2=value2" and then sent as a query string.
     *
     * @param file
     *         the absolute path of the file
     * @param form_data
     *         an array of Name/Value pairs
     * @param headers
     *         additional headers
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Get(String file, NVPair[] form_data, NVPair[] headers) throws IOException, ModuleException {
        String File = stripRef(file), query = Codecs.nv2query(form_data);
        if (query != null && query.length() > 0)
            File += "?" + query;

        return setupRequest("GET", File, headers, null, null);
    }

    /**
     * GETs the file using the specified query string. The query string is first
     * urlencoded.
     *
     * @param file
     *         the absolute path of the file
     * @param query
     *         the query
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Get(String file, String query) throws IOException, ModuleException {
        return Get(file, query, null);
    }

    /**
     * GETs the file using the specified query string. The query string is first
     * urlencoded.
     *
     * @param file
     *         the absolute path of the file
     * @param query
     *         the query string
     * @param headers
     *         additional headers
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Get(String file, String query, NVPair[] headers) throws IOException, ModuleException {
        String File = stripRef(file);
        if (query != null && query.length() > 0)
            File += "?" + Codecs.URLEncode(query);

        return setupRequest("GET", File, headers, null, null);
    }

    /**
     * POSTs to the specified file. No data is sent.
     *
     * @param file
     *         the absolute path of the file
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Post(String file) throws IOException, ModuleException {
        return Post(file, (byte[])null, null);
    }

    /**
     * POSTs form-data to the specified file. The data is first urlencoded and
     * then turned into a string of the form "name1=value1&name2=value2". A
     * <var>Content-type</var> header with the value
     * <var>application/x-www-form-urlencoded</var> is added.
     *
     * @param file
     *         the absolute path of the file
     * @param form_data
     *         an array of Name/Value pairs
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Post(String file, NVPair form_data[]) throws IOException, ModuleException {
        NVPair[] headers = {new NVPair("Content-type", "application/x-www-form-urlencoded")};

        return Post(file, Codecs.nv2query(form_data), headers);
    }

    /**
     * POST's form-data to the specified file using the specified headers. The
     * data is first urlencoded and then turned into a string of the form
     * "name1=value1&name2=value2". If no <var>Content-type</var> header is given
     * then one is added with a value of
     * <var>application/x-www-form-urlencoded</var>.
     *
     * @param file
     *         the absolute path of the file
     * @param form_data
     *         an array of Name/Value pairs
     * @param headers
     *         additional headers
     * @return a HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Post(String file, NVPair form_data[], NVPair headers[]) throws IOException, ModuleException {
        int idx;
        for (idx = 0; idx < headers.length; idx++)
            if (headers[idx].getName().equalsIgnoreCase("Content-type"))
                break;
        if (idx == headers.length) {
            headers = Util.resizeArray(headers, idx + 1);
            headers[idx] = new NVPair("Content-type", "application/x-www-form-urlencoded");
        }

        return Post(file, Codecs.nv2query(form_data), headers);
    }

    /**
     * POSTs the data to the specified file. The data is converted to an array of
     * bytes using the default character converter. The request is sent using the
     * content-type "application/octet-stream".
     *
     * @param file
     *         the absolute path of the file
     * @param data
     *         the data
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     * @see java.lang.String#getBytes()
     */
    public HTTPResponse Post(String file, String data) throws IOException, ModuleException {
        return Post(file, data, null);
    }

    /**
     * POSTs the data to the specified file using the specified headers.
     *
     * @param file
     *         the absolute path of the file
     * @param data
     *         the data
     * @param headers
     *         additional headers
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     * @see java.lang.String#getBytes()
     */
    public HTTPResponse Post(String file, String data, NVPair[] headers) throws IOException, ModuleException {
        byte tmp[] = null;

        if (data != null && data.length() > 0)
            tmp = data.getBytes();

        return Post(file, tmp, headers);
    }

    /**
     * POSTs the raw data to the specified file. The request is sent using the
     * content-type "application/octet-stream"
     *
     * @param file
     *         the absolute path of the file
     * @param data
     *         the data
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Post(String file, byte data[]) throws IOException, ModuleException {
        return Post(file, data, null);
    }

    /**
     * POSTs the raw data to the specified file using the specified headers.
     *
     * @param file
     *         the absolute path of the file
     * @param data
     *         the data
     * @param headers
     *         additional headers
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Post(String file, byte data[], NVPair[] headers) throws IOException, ModuleException {
        if (data == null)
            data = new byte[0]; // POST must always have a CL
        return setupRequest("POST", stripRef(file), headers, data, null);
    }

    /**
     * POSTs the data written to the output stream to the specified file. The
     * request is sent using the content-type "application/octet-stream"
     *
     * @param file
     *         the absolute path of the file
     * @param stream
     *         the output stream on which the data is written
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Post(String file, HttpOutputStream stream) throws IOException, ModuleException {
        return Post(file, stream, null);
    }

    /**
     * POSTs the data written to the output stream to the specified file using
     * the specified headers.
     *
     * @param file
     *         the absolute path of the file
     * @param stream
     *         the output stream on which the data is written
     * @param headers
     *         additional headers
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Post(String file, HttpOutputStream stream, NVPair[] headers) throws IOException, ModuleException {
        return setupRequest("POST", stripRef(file), headers, null, stream);
    }

    /**
     * PUTs the data into the specified file. The data is converted to an array
     * of bytes using the default character converter. The request ist sent using
     * the content-type "application/octet-stream".
     *
     * @param file
     *         the absolute path of the file
     * @param data
     *         the data
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     * @see java.lang.String#getBytes()
     */
    public HTTPResponse Put(String file, String data) throws IOException, ModuleException {
        return Put(file, data, null);
    }

    /**
     * PUTs the data into the specified file using the additional headers for the
     * request.
     *
     * @param file
     *         the absolute path of the file
     * @param data
     *         the data
     * @param headers
     *         additional headers
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     * @see java.lang.String#getBytes()
     */
    public HTTPResponse Put(String file, String data, NVPair[] headers) throws IOException, ModuleException {
        byte tmp[] = null;

        if (data != null && data.length() > 0)
            tmp = data.getBytes();

        return Put(file, tmp, headers);
    }

    /**
     * PUTs the raw data into the specified file. The request is sent using the
     * content-type "application/octet-stream".
     *
     * @param file
     *         the absolute path of the file
     * @param data
     *         the data
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Put(String file, byte data[]) throws IOException, ModuleException {
        return Put(file, data, null);
    }

    /**
     * PUTs the raw data into the specified file using the additional headers.
     *
     * @param file
     *         the absolute path of the file
     * @param data
     *         the data
     * @param headers
     *         any additional headers
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Put(String file, byte data[], NVPair[] headers) throws IOException, ModuleException {
        if (data == null)
            data = new byte[0]; // PUT must always have a CL
        return setupRequest("PUT", stripRef(file), headers, data, null);
    }

    /**
     * PUTs the data written to the output stream into the specified file. The
     * request is sent using the content-type "application/octet-stream".
     *
     * @param file
     *         the absolute path of the file
     * @param stream
     *         the output stream on which the data is written
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Put(String file, HttpOutputStream stream) throws IOException, ModuleException {
        return Put(file, stream, null);
    }

    /**
     * PUTs the data written to the output stream into the specified file using
     * the additional headers.
     *
     * @param file
     *         the absolute path of the file
     * @param stream
     *         the output stream on which the data is written
     * @param headers
     *         any additional headers
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Put(String file, HttpOutputStream stream, NVPair[] headers) throws IOException, ModuleException {
        return setupRequest("PUT", stripRef(file), headers, null, stream);
    }

    /**
     * Request OPTIONS from the server. If <var>file</var> is "*" then the
     * request applies to the server as a whole; otherwise it applies only to
     * that resource.
     *
     * @param file
     *         the absolute path of the resource, or "*"
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Options(String file) throws IOException, ModuleException {
        return Options(file, null, (byte[])null);
    }

    /**
     * Request OPTIONS from the server. If <var>file</var> is "*" then the
     * request applies to the server as a whole; otherwise it applies only to
     * that resource.
     *
     * @param file
     *         the absolute path of the resource, or "*"
     * @param headers
     *         the headers containing optional info.
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Options(String file, NVPair[] headers) throws IOException, ModuleException {
        return Options(file, headers, (byte[])null);
    }

    /**
     * Request OPTIONS from the server. If <var>file</var> is "*" then the
     * request applies to the server as a whole; otherwise it applies only to
     * that resource.
     *
     * @param file
     *         the absolute path of the resource, or "*"
     * @param headers
     *         the headers containing optional info.
     * @param data
     *         any data to be sent in the optional body
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Options(String file, NVPair[] headers, byte[] data) throws IOException, ModuleException {
        return setupRequest("OPTIONS", stripRef(file), headers, data, null);
    }

    /**
     * Request OPTIONS from the server. If <var>file</var> is "*" then the
     * request applies to the server as a whole; otherwise it applies only to
     * that resource.
     *
     * @param file
     *         the absolute path of the resource, or "*"
     * @param headers
     *         the headers containing optional info.
     * @param stream
     *         an output stream for sending the optional body
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Options(String file, NVPair[] headers, HttpOutputStream stream) throws IOException,
                                                                                               ModuleException {
        return setupRequest("OPTIONS", stripRef(file), headers, null, stream);
    }

    /**
     * Requests that <var>file</var> be DELETEd from the server.
     *
     * @param file
     *         the absolute path of the resource
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Delete(String file) throws IOException, ModuleException {
        return Delete(file, null);
    }

    /**
     * Requests that <var>file</var> be DELETEd from the server.
     *
     * @param file
     *         the absolute path of the resource
     * @param headers
     *         additional headers
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Delete(String file, NVPair[] headers) throws IOException, ModuleException {
        return setupRequest("DELETE", stripRef(file), headers, null, null);
    }

    /**
     * Requests a TRACE. Headers of particular interest here are "Via" and
     * "Max-Forwards".
     *
     * @param file
     *         the absolute path of the resource
     * @param headers
     *         additional headers
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Trace(String file, NVPair[] headers) throws IOException, ModuleException {
        return setupRequest("TRACE", stripRef(file), headers, null, null);
    }

    /**
     * Requests a TRACE.
     *
     * @param file
     *         the absolute path of the resource
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Trace(String file) throws IOException, ModuleException {
        return Trace(file, null);
    }

    // webdav specific methods

    /**
     * Copy resource or colleaction to URL spesified in <code>destination</code>
     * parameter. If destination resource exist operation will be fail.
     *
     * @param source
     *         the source URL.
     * @param destination
     *         the destination URL.
     * @param override
     *         must destination resource be overwrite.
     * @param norecursive
     *         on collection resource it means copy only resource but
     *         not child.
     * @return an HTTPResponse structure containing the response.
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Copy(String source, String destination, boolean override, boolean norecursive)
            throws IOException, ModuleException {
        NVPair destinationPair = new NVPair("Destination", destination);
        NVPair overridePair = new NVPair("Overwrite", override ? "T" : "F");
        NVPair depthPair = new NVPair("Depth", norecursive ? "0" : "infinity");
        return setupRequest("COPY", source, new NVPair[]{destinationPair, overridePair, depthPair}, null, null);
    }

    /**
     * Copy resource or colleaction to URL spesified in <code>destination</code>
     * parameter. If destination resource exist operation will be fail.
     *
     * @param source
     *         the source URL.
     * @param destination
     *         the destination URL.
     * @return an HTTPResponse structure containing the response.
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Copy(String source, String destination) throws IOException, ModuleException {
        return Copy(source, destination, false, false);
    }

    /**
     * Move resource or colleaction to URL spesified in <code>destination</code>
     * parameter.
     *
     * @param source
     *         the source URL.
     * @param destination
     *         the destination URL.
     * @param override
     *         must destination resource be overwrite.
     * @return an HTTPResponse structure containing the response.
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Move(String source, String destination, boolean override) throws IOException, ModuleException {
        NVPair destinationPair = new NVPair("Destination", destination);
        NVPair overridePair = new NVPair("Overwrite", override ? "T" : "F");
        return setupRequest("MOVE", source, new NVPair[]{destinationPair, overridePair}, null, null);
    }

    /**
     * Move resource or colleaction to URL spesified in <code>destination</code>
     * parameter. If destination resource exist operation will be fail.
     *
     * @param source
     *         the source URL.
     * @param destination
     *         the destination URL.
     * @return an HTTPResponse structure containing the response.
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Move(String source, String destination) throws IOException, ModuleException {
        return Move(source, destination, false);
    }

    /**
     * Create new Collection.
     *
     * @param resource
     *         the URL for Collection creation.
     * @return an HTTPResponse structure containing the response.
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse MkCol(String resource) throws IOException, ModuleException {
        return setupRequest("MKCOL", resource, null, null, null);
    }

    /**
     * PROPFIND allprop request with 'Depth' header specified as 'infinity'.
     *
     * @param resource
     *         resource's URL.
     * @param depth
     *         the depth of request, if specified as -1 then 'infinity' will
     *         be used.
     * @return an HTTPResponse structure containing the response.
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse PropfindAllprop(String resource, int depth) throws IOException, ModuleException {
        byte[] requestBody =
                "<?xml version='1.0' encoding='utf-8'?><D:propfind xmlns:D=\"DAV:\"><D:allprop/></D:propfind>".getBytes();

        NVPair depthPair = new NVPair("Depth", depth == -1 ? "infinity" : (depth + ""));
        NVPair contentTypePair = new NVPair("Content-Type", "text/xml");
        NVPair contentLenghtPair = new NVPair("Content-Lenght", "" + requestBody.length);
        return setupRequest("PROPFIND", resource, new NVPair[]{depthPair, contentTypePair, contentLenghtPair},
                            requestBody, null);
    }

    /**
     * PROPFIND allprop request with 'Depth' header specified as 'infinity'.
     *
     * @param resource
     *         resource's URL.
     * @return an HTTPResponse structure containing the response.
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse PropfindAllprop(String resource) throws IOException, ModuleException {
        return PropfindAllprop(resource, -1);
    }

    /**
     * PROPFIND prop request.
     *
     * @param resource
     *         resource's URL.
     * @param props
     *         the List&lt;String&gt; of resource's properties.
     * @param depth
     *         the depth of request, if specified as -1 then 'infinity' will
     *         be used.
     * @return an HTTPResponse structure containing the response.
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Propfind(String resource, List<String> props, int depth) throws IOException, ModuleException {
        XMLOutputFactory factory = XMLOutputFactory.newInstance();
        HttpOutputStream out = new HttpOutputStream();
        NVPair depthPair = new NVPair("Depth", depth == -1 ? "infinity" : (depth + ""));
        NVPair contentTypePair = new NVPair("Content-Type", "text/xml");
        HTTPResponse response = setupRequest("PROPFIND", resource, new NVPair[]{depthPair, contentTypePair}, null, out);
        try {
            XMLStreamWriter sw = factory.createXMLStreamWriter(out, "UTF-8");
            sw.writeStartDocument("UTF-8", "1.0");
            sw.writeStartElement("D", "propfind", "DAV:");
            sw.writeNamespace("D", "DAV:");
            sw.writeStartElement("D", "prop", "DAV:");
            for (String prop : props)
                sw.writeEmptyElement("D", prop, "DAV:");

            sw.writeEndElement(); // prop
            sw.writeEndElement(); // propfind
            sw.writeEndDocument();
            out.close();
        } catch (XMLStreamException e) {
            LOG.error(e.getMessage(), e);
            throw new IOException("Can't write XML data to output stream.");
        }
        return response;
    }

    /**
     * PROPFIND prop request with 'Depth' header specified as 'infinity'.
     *
     * @param resource
     *         resource's URL.
     * @param props
     *         the List&lt;String&gt; of resource's properties.
     * @return an HTTPResponse structure containing the response.
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Propfind(String resource, List<String> props) throws IOException, ModuleException {
        return Propfind(resource, props, -1);
    }

    /**
     * PROPFIND propname request.
     *
     * @param resource
     *         resource's URL.
     * @param depth
     *         the depth of request, if specified as -1 then 'infinity' will
     *         be used.
     * @return an HTTPResponse structure containing the response.
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse PropfindPropname(String resource, int depth) throws IOException, ModuleException {
        byte[] requestBody =
                "<?xml version='1.0' encoding='utf-8'?><D:propfind xmlns:D=\"DAV:\"><D:propname/></D:propfind>".getBytes();

        NVPair depthPair = new NVPair("Depth", depth == -1 ? "infinity" : (depth + ""));
        NVPair contentTypePair = new NVPair("Content-Type", "text/xml");
        NVPair contentLenghtPair = new NVPair("Content-Lenght", "" + requestBody.length);
        return setupRequest("PROPFIND", resource, new NVPair[]{depthPair, contentTypePair, contentLenghtPair},
                            requestBody, null);
    }

    /**
     * PROPFIND propname request with 'Depth' header specified as 'infinity'.
     *
     * @param resource
     *         resource's URL.
     * @return an HTTPResponse structure containing the response.
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse PropfindPropname(String resource) throws IOException, ModuleException {
        return PropfindPropname(resource, -1);
    }

    /**
     * PROPPATCH request.
     *
     * @param resource
     *         resource's URL.
     * @param propsSet
     *         properties for set.
     * @param propsRemove
     *         properties for remove.
     * @return an HTTPResponse structure containing the response.
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Proppath(String resource, Map<String, List<String>> propsSet, List<String> propsRemove)
            throws IOException, ModuleException {

        XMLOutputFactory factory = XMLOutputFactory.newInstance();
        HttpOutputStream out = new HttpOutputStream();
        NVPair contentTypePair = new NVPair("Content-Type", "text/xml");
        HTTPResponse response = setupRequest("PROPPATCH", resource, new NVPair[]{contentTypePair}, null, out);

        try {
            XMLStreamWriter sw = factory.createXMLStreamWriter(out, "UTF-8");
            sw.writeStartDocument("UTF-8", "1.0");
            sw.writeStartElement("D", "propertyupdate", "DAV:");
            sw.writeNamespace("D", "DAV:");
            if (propsSet != null && propsSet.size() > 0) {
                sw.writeStartElement("D", "set", "DAV:");
                Iterator<String> propsSetIter = propsSet.keySet().iterator();
                while (propsSetIter.hasNext()) {
                    String prop = propsSetIter.next();
                    List<String> values = propsSet.get(prop);
                    if (values != null && values.size() > 0) {
                        sw.writeStartElement("D", "prop", "DAV:");
                        for (String value : values) {
                            sw.writeStartElement("D", prop, "DAV:");
                            sw.writeCharacters(value);
                            sw.writeEndElement();
                        }
                        sw.writeEndElement(); // prop
                    }
                }
                sw.writeEndElement(); // set
            }

            if (propsRemove != null && propsRemove.size() > 0) {
                sw.writeStartElement("D", "remove", "DAV:");
                for (String value : propsRemove) {
                    sw.writeStartElement("D", "prop", "DAV:");
                    sw.writeEmptyElement(value);
                    sw.writeEndElement(); // prop
                }
                sw.writeEndElement(); // remove
            }

            sw.writeEndElement(); // propertyupdate

            sw.writeEndDocument();
            out.close();
        } catch (XMLStreamException e) {
            LOG.error(e.getMessage(), e);
            throw new IOException("Can't write XML data to output stream.");
        }
        return response;
    }

    /**
     * LOCK request
     *
     * @param resource
     *         resource's URL.
     * @param isExclusive
     *         if true then exclusive type of lock will be set
     *         otherwise shared lock.
     * @param isRecursive
     *         if true then lock on collection will be recursive
     *         otherwise child resource will be not locked.
     * @param timeout
     *         the timeout for lock, if -1 then 'infinity' will be send.
     * @return an HTTPResponse structure containing the response.
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Lock(String resource, boolean isExclusive, boolean isRecursive, long timeout)
            throws IOException, ModuleException {

        HttpOutputStream out = new HttpOutputStream();

        NVPair contentTypePair = new NVPair("Content-Type", "text/xml");
        NVPair depthPair = new NVPair("Depth", isRecursive ? "Infinity" : "0");
        NVPair timeoutPair = new NVPair("Timeout", timeout == -1 ? "Infinity" : "Second-" + timeout);
        HTTPResponse response =
                setupRequest("LOCK", resource, new NVPair[]{contentTypePair, timeoutPair, depthPair}, null, out);
        try {
            XMLOutputFactory factory = XMLOutputFactory.newInstance();
            XMLStreamWriter sw = factory.createXMLStreamWriter(out, "UTF-8");
            sw.writeStartDocument("UTF-8", "1.0");
            sw.writeStartElement("D", "lockinfo", "DAV:");
            sw.writeNamespace("D", "DAV:");
            sw.writeStartElement("D", "lockscope", "DAV:");
            if (isExclusive)
                sw.writeEmptyElement("D", "exclusive", "DAV:");
            else
                sw.writeEmptyElement("D", "shared", "DAV:");
            sw.writeEndElement(); // lockscope
            sw.writeStartElement("D", "locktype", "DAV:");
            sw.writeEmptyElement("D", "write", "DAV:");
            sw.writeEndElement(); // locktype
            sw.writeStartElement("D", "owner", "DAV:");
            sw.writeStartElement("D", "href", "DAV:");
            sw.writeCharacters("http://exoplatform.org");
            sw.writeEndElement(); // href
            sw.writeEndElement(); // owner
            sw.writeEndElement(); // lockinfo
            sw.writeEndDocument();

        } catch (XMLStreamException e) {
            LOG.error(e.getMessage(), e);
            throw new IOException("Can't write XML request.");
        } finally {
            out.close();
        }
        return response;
    }

    /**
     * Refresh LOCK request.
     *
     * @param resource
     *         resource's URL.
     * @param timeout
     *         the timeout for lock, if -1 then 'infinity' will be send.
     * @param lockToken
     *         the locktoken.
     * @return an HTTPResponse structure containing the response.
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Lock(String resource, long timeout, String lockToken) throws IOException, ModuleException {
        NVPair timeoutPair = new NVPair("Timeout", timeout == -1 ? "Infinity" : "Second-" + timeout);
        NVPair ifPair =
                new NVPair("If", lockToken.startsWith("opaquelocktoken:") ? "(<" + lockToken + ">)" : "(<opaquelocktoken:"
                                                                                                      + lockToken + ">)");
        return setupRequest("LOCK", resource, new NVPair[]{timeoutPair, ifPair}, null, null);

    }

    /**
     * Refresh LOCK request.
     *
     * @param resource
     *         resource's URL.
     * @param timeout
     *         the timeout for lock, if -1 then 'infinity' will be send.
     * @param lockToken
     *         the locktoken.
     * @return an HTTPResponse structure containing the response.
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse Unlock(String resource, String lockToken) throws IOException, ModuleException {
        NVPair locktokenPair =
                new NVPair("Lock-Token", lockToken.startsWith("opaquelocktoken:") ? "<" + lockToken + ">"
                                                                                  : "<opaquelocktoken:" + lockToken + ">");
        return setupRequest("UNLOCK", resource, new NVPair[]{locktokenPair}, null, null);
    }

    // end webdav specific methods

    /**
     * This is here to allow an arbitrary, non-standard request to be sent. I'm
     * assuming you know what you are doing...
     *
     * @param method
     *         the extension method
     * @param file
     *         the absolute path of the resource, or null
     * @param data
     *         optional data, or null
     * @param headers
     *         optional headers, or null
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse ExtensionMethod(String method, String file, byte[] data, NVPair[] headers) throws IOException,
                                                                                                          ModuleException {
        return setupRequest(method.trim(), stripRef(file), headers, data, null);
    }

    /**
     * This is here to allow an arbitrary, non-standard request to be sent. I'm
     * assuming you know what you are doing...
     *
     * @param method
     *         the extension method
     * @param file
     *         the absolute path of the resource, or null
     * @param stream
     *         optional output stream, or null
     * @param headers
     *         optional headers, or null
     * @return an HTTPResponse structure containing the response
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    public HTTPResponse ExtensionMethod(String method, String file, HttpOutputStream os, NVPair[] headers)
            throws IOException, ModuleException {
        return setupRequest(method.trim(), stripRef(file), headers, null, os);
    }

    /**
     * Aborts all the requests currently in progress on this connection and
     * closes all associated sockets. You usually do <em>not</em> need to invoke
     * this - it only meant for when you need to abruptly stop things, such as
     * for example the stop button in a browser.
     * <p/>
     * Note: there is a small window where a request method such as
     * <code>Get()</code> may have been invoked but the request has not been
     * built and added to the list. Any request in this window will not be
     * aborted.
     *
     * @since V0.2-3
     */
    public void stop() {
        for (Request req = (Request)RequestList.enumerate(); req != null; req = (Request)RequestList.next())
            req.aborted = true;

        for (StreamDemultiplexor demux = (StreamDemultiplexor)DemuxList.enumerate(); demux != null; demux =
                (StreamDemultiplexor)DemuxList.next())
            demux.abort();
    }

    /**
     * Sets the default http headers to be sent with each request. The actual
     * headers sent are determined as follows: for each header specified in
     * multiple places a value given as part of the request takes priority over
     * any default values set by this method, which in turn takes priority over
     * any built-in default values. A different way of looking at it is that we
     * start off with a list of all headers specified with the request, then add
     * any default headers set by this method which aren't already in our list,
     * and finally add any built-in headers which aren't yet in the list. There
     * is one exception to this rule: the "Content-length" header is always
     * ignored; and when posting form-data any default "Content-type" is ignored
     * in favor of the built-in "application/x-www-form-urlencoded" (however it
     * will be overriden by any content-type header specified as part of the
     * request).
     * <p/>
     * Typical headers you might want to set here are "Accept" and its "Accept-*"
     * relatives, "Connection", "From", "User-Agent", etc.
     *
     * @param headers
     *         an array of header-name/value pairs (do not give the
     *         separating ':').
     */
    public void setDefaultHeaders(NVPair[] headers) {
        int length = (headers == null ? 0 : headers.length);
        NVPair[] def_hdrs = new NVPair[length];

        // weed out undesired headers
        int sidx, didx;
        for (sidx = 0, didx = 0; sidx < length; sidx++) {
            if (headers[sidx] == null)
                continue;

            String name = headers[sidx].getName().trim();
            if (name.equalsIgnoreCase("Content-length"))
                continue;

            def_hdrs[didx++] = headers[sidx];
        }

        if (didx < length)
            def_hdrs = Util.resizeArray(def_hdrs, didx);

        synchronized (DefaultHeaders) {
            DefaultHeaders = def_hdrs;
        }
    }

    /**
     * Gets the current list of default http headers.
     *
     * @return an array of header/value pairs.
     */
    public NVPair[] getDefaultHeaders() {
        synchronized (DefaultHeaders) {
            return DefaultHeaders.clone();
        }
    }

    /**
     * Returns the protocol this connection is talking.
     *
     * @return a string containing the (lowercased) protocol
     */
    public String getProtocol() {
        switch (Protocol) {
            case HTTP:
                return "http";
            case HTTPS:
                return "https";
            case SHTTP:
                return "shttp";
            case HTTP_NG:
                return "http-ng";
            default:
                throw new Error("HTTPClient Internal Error: invalid protocol " + Protocol);
        }
    }

    /**
     * Returns the host this connection is talking to.
     *
     * @return a string containing the (lowercased) host name.
     */
    public String getHost() {
        return Host;
    }

    /**
     * Returns the port this connection connects to. This is always the actual
     * port number, never -1.
     *
     * @return the port number
     */
    public int getPort() {
        return Port;
    }

    /**
     * Returns the host of the proxy this connection is using.
     *
     * @return a string containing the (lowercased) host name.
     */
    public String getProxyHost() {
        return Proxy_Host;
    }

    /**
     * Returns the port of the proxy this connection is using.
     *
     * @return the port number
     */
    public int getProxyPort() {
        return Proxy_Port;
    }

    /**
     * See if the given uri is compatible with this connection. Compatible means
     * that the given uri can be retrieved using this connection object.
     *
     * @param uri
     *         the URI to check
     * @return true if they're compatible, false otherwise
     * @since V0.3-2
     */
    public boolean isCompatibleWith(URI uri) {
        if (!uri.getScheme().equals(getProtocol()) || !uri.getHost().equalsIgnoreCase(Host))
            return false;

        int port = uri.getPort();
        if (port == -1)
            port = URI.defaultPort(uri.getScheme());
        return port == Port;
    }

    /**
     * Sets/Resets raw mode. In raw mode all modules are bypassed, meaning the
     * automatic handling of authorization requests, redirections, cookies, etc.
     * is turned off.
     * <p/>
     * The default is false.
     *
     * @param raw
     *         if true removes all modules (except for the retry module)
     * @see #removeModule(java.lang.Class)
     * @deprecated This is not really needed anymore; in V0.2 request were
     *             synchronous and therefore to do pipelining you needed to
     *             disable the processing of responses.
     */
    public void setRawMode(boolean raw) {
        // Don't remove the retry module
        String[] modules =
                {"HTTPClient.CookieModule", "HTTPClient.RedirectionModule", "HTTPClient.AuthorizationModule",
                 "HTTPClient.DefaultModule", "HTTPClient.TransferEncodingModule", "HTTPClient.ContentMD5Module",
                 "HTTPClient.ContentEncodingModule"};

        for (int idx = 0; idx < modules.length; idx++) {
            try {
                if (raw)
                    removeModule(Class.forName(modules[idx]));
                else
                    addModule(Class.forName(modules[idx]), -1);
            } catch (ClassNotFoundException cnfe) {
            }
        }
    }

    /**
     * Sets the default timeout value to be used for each new HTTPConnection. The
     * default is 0.
     *
     * @param time
     *         the timeout in milliseconds.
     * @see #setTimeout(int)
     */
    public static void setDefaultTimeout(int time) {
        DefaultTimeout = time;
    }

    /**
     * Gets the default timeout value to be used for each new HTTPConnection.
     *
     * @return the timeout in milliseconds.
     * @see #setTimeout(int)
     */
    public static int getDefaultTimeout() {
        return DefaultTimeout;
    }

    /**
     * Sets the timeout to be used for creating connections and reading
     * responses. When a timeout expires the operation will throw an
     * InterruptedIOException. The operation may be restarted again afterwards.
     * If the operation is not restarted and it is a read operation (i.e
     * HTTPResponse.xxxx()) then <code>resp.getInputStream().close()</code>
     * <strong>should</strong> be invoked.
     * <p/>
     * When creating new sockets the timeout will limit the time spent doing the
     * host name translation and establishing the connection with the server.
     * <p/>
     * The timeout also influences the reading of the response headers. However,
     * it does not specify a how long, for example, getStatusCode() may take, as
     * might be assumed. Instead it specifies how long a read on the socket may
     * take. If the response dribbles in slowly with packets arriving quicker
     * than the timeout then the method will complete normally. I.e. the
     * exception is only thrown if nothing arrives on the socket for the
     * specified time. Furthermore, the timeout only influences the reading of
     * the headers, not the reading of the body.
     * <p/>
     * Read Timeouts are associated with responses, so that you may change this
     * value before each request and it won't affect the reading of responses to
     * previous requests.
     *
     * @param time
     *         the time in milliseconds. A time of 0 means wait indefinitely.
     * @see #stop()
     */
    public void setTimeout(int time) {
        Timeout = time;
    }

    /**
     * Gets the timeout used for reading response data.
     *
     * @return the current timeout value
     * @see #setTimeout(int)
     */
    public int getTimeout() {
        return Timeout;
    }

    /**
     * Controls whether modules are allowed to prompt the user or pop up dialogs
     * if neccessary.
     *
     * @param allow
     *         if true allows modules to interact with user.
     */
    public void setAllowUserInteraction(boolean allow) {
        allowUI = allow;
    }

    /**
     * returns whether modules are allowed to prompt or popup dialogs if
     * neccessary.
     *
     * @return true if modules are allowed to interact with user.
     */
    public boolean getAllowUserInteraction() {
        return allowUI;
    }

    /**
     * Sets the default allow-user-action.
     *
     * @param allow
     *         if true allows modules to interact with user.
     */
    public static void setDefaultAllowUserInteraction(boolean allow) {
        defaultAllowUI = allow;
    }

    /**
     * Gets the default allow-user-action.
     *
     * @return true if modules are allowed to interact with user.
     */
    public static boolean getDefaultAllowUserInteraction() {
        return defaultAllowUI;
    }

    /**
     * Returns the default list of modules.
     *
     * @return an array of classes
     */
    public static Class[] getDefaultModules() {
        return getModules(DefaultModuleList);
    }

    /**
     * Adds a module to the default list. It must implement the
     * <var>HTTPClientModule</var> interface. If the module is already in the
     * list then this method does nothing. This method only affects instances of
     * HTTPConnection created after this method has been invoked; it does not
     * affect existing instances.
     * <p/>
     * Example:
     * <p/>
     * <PRE>
     * HTTPConnection.addDefaultModule(Class.forName(&quot;HTTPClient.CookieModule&quot;), 1);
     * </PRE>
     * <p/>
     * adds the cookie module as the second module in the list.
     * <p/>
     * The default list is created at class initialization time from the property
     * <var>HTTPClient.Modules</var>. This must contain a "|" separated list of
     * classes in the order they're to be invoked. If this property is not set it
     * defaults to: "HTTPClient.RetryModule | HTTPClient.CookieModule |
     * HTTPClient.RedirectionModule | HTTPClient.AuthorizationModule |
     * HTTPClient.DefaultModule | HTTPClient.TransferEncodingModule |
     * HTTPClient.ContentMD5Module | HTTPClient.ContentEncodingModule"
     *
     * @param module
     *         the module's Class object
     * @param pos
     *         the position of this module in the list; if <var>pos</var> >= 0
     *         then this is the absolute position in the list (0 is the first
     *         position); if <var>pos</var> < 0 then this is the position relative
     *         to the end of the list (-1 means the last element, -2 the second to
     *         last element, etc).
     * @return true if module was successfully added; false if the module is
     *         already in the list.
     * @throws ArrayIndexOutOfBoundsException
     *         if <var>pos</var> > list-size or
     *         if <var>pos</var> < -(list-size).
     * @throws ClassCastException
     *         if <var>module</var> does not implement the
     *         <var>HTTPClientModule</var> interface.
     * @throws RuntimeException
     *         if <var>module</var> cannot be instantiated.
     * @see HTTPClientModule
     */
    public static boolean addDefaultModule(Class module, int pos) {
        return addModule(DefaultModuleList, module, pos);
    }

    /**
     * Removes a module from the default list. If the module is not in the list
     * it does nothing. This method only affects instances of HTTPConnection
     * created after this method has been invoked; it does not affect existing
     * instances.
     *
     * @param module
     *         the module's Class object
     * @return true if module was successfully removed; false otherwise
     */
    public static boolean removeDefaultModule(Class module) {
        return removeModule(DefaultModuleList, module);
    }

    /**
     * Returns the list of modules used currently.
     *
     * @return an array of classes
     */
    public Class[] getModules() {
        return getModules(ModuleList);
    }

    /**
     * Adds a module to the current list. It must implement the
     * <var>HTTPClientModule</var> interface. If the module is already in the
     * list then this method does nothing.
     *
     * @param module
     *         the module's Class object
     * @param pos
     *         the position of this module in the list; if <var>pos</var> >= 0
     *         then this is the absolute position in the list (0 is the first
     *         position); if <var>pos</var> < 0 then this is the position relative
     *         to the end of the list (-1 means the last element, -2 the second to
     *         last element, etc).
     * @return true if module was successfully added; false if the module is
     *         already in the list.
     * @throws ArrayIndexOutOfBoundsException
     *         if <var>pos</var> > list-size or
     *         if <var>pos</var> < -(list-size).
     * @throws ClassCastException
     *         if <var>module</var> does not implement the
     *         <var>HTTPClientModule</var> interface.
     * @throws RuntimeException
     *         if <var>module</var> cannot be instantiated.
     * @see HTTPClientModule
     */
    public boolean addModule(Class module, int pos) {
        return addModule(ModuleList, module, pos);
    }

    /**
     * Removes a module from the current list. If the module is not in the list
     * it does nothing.
     *
     * @param module
     *         the module's Class object
     * @return true if module was successfully removed; false otherwise
     */
    public boolean removeModule(Class module) {
        return removeModule(ModuleList, module);
    }

    private static final Class[] getModules(Vector list) {
        synchronized (list) {
            Class[] modules = new Class[list.size()];
            list.copyInto(modules);
            return modules;
        }
    }

    private static final boolean addModule(Vector list, Class module, int pos) {
        if (module == null)
            return false;

        // check if module implements HTTPClientModule
        try {
            HTTPClientModule tmp = (HTTPClientModule)module.newInstance();
        } catch (RuntimeException re) {
            throw re;
        } catch (Exception e) {
            throw new RuntimeException(e.toString());
        }

        synchronized (list) {
            // check if module already in list
            if (list.contains(module))
                return false;

            // add module to list
            if (pos < 0)
                list.insertElementAt(module, DefaultModuleList.size() + pos + 1);
            else
                list.insertElementAt(module, pos);
        }

        if (log.isDebugEnabled())
            log.debug("Added module " + module.getName() + " to " + ((list == DefaultModuleList) ? "default " : "")
                      + "list");

        return true;
    }

    private static final boolean removeModule(Vector list, Class module) {
        if (module == null)
            return false;

        boolean removed = list.removeElement(module);
        if (removed) {
            if (log.isDebugEnabled())
                log.debug("Removed module " + module.getName() + " from " + ((list == DefaultModuleList) ? "default " : "")
                          + "list");

        }

        return removed;
    }

    /**
     * Sets the current context. The context is used by modules such as the
     * AuthorizationModule and the CookieModule which keep lists of info that is
     * normally shared between all instances of HTTPConnection. This is usually
     * the desired behaviour. However, in some cases one would like to simulate
     * multiple independent clients within the same application and hence the
     * sharing of such info should be restricted. This is where the context comes
     * in. Modules will only share their info between requests using the same
     * context (i.e. they keep multiple lists, one for each context).
     * <p/>
     * The context may be any object. Contexts are considered equal if
     * <code>equals()</code> returns true. Examples of useful context objects are
     * threads (e.g. if you are running multiple clients, one per thread) and
     * sockets (e.g. if you are implementing a gateway).
     * <p/>
     * When a new HTTPConnection is created it is initialized with a default
     * context which is the same for all instances. This method must be invoked
     * immediately after a new HTTPConnection is created and before any request
     * method is invoked. Furthermore, this method may only be called once (i.e.
     * the context is "sticky").
     *
     * @param context
     *         the new context; must be non-null
     * @throws IllegalArgumentException
     *         if <var>context</var> is null
     * @throws IllegalStateException
     *         if the context has already been set
     */
    public void setContext(Object context) {
        if (context == null)
            throw new IllegalArgumentException("Context must be non-null");
        if (Context != null)
            throw new IllegalStateException("Context already set");

        Context = context;
    }

    /**
     * Returns the current context.
     *
     * @return the current context, or the default context if
     *         <code>setContext()</code> hasn't been invoked
     * @see #setContext(java.lang.Object)
     */
    public Object getContext() {
        if (Context != null)
            return Context;
        else
            return dflt_context;
    }

    /**
     * Returns the default context.
     *
     * @return the default context
     * @see #setContext(java.lang.Object)
     */
    public static Object getDefaultContext() {
        return dflt_context;
    }

    /**
     * Adds an authorization entry for the "digest" authorization scheme to the
     * list. If an entry already exists for the "digest" scheme and the specified
     * realm then it is overwritten.
     * <p/>
     * This is a convenience method and just invokes the corresponding method in
     * AuthorizationInfo.
     *
     * @param realm
     *         the realm
     * @param user
     *         the username
     * @param passw
     *         the password
     * @see AuthorizationInfo#addDigestAuthorization(java.lang.String, int,
     *      java.lang.String, java.lang.String, java.lang.String)
     */
    public void addDigestAuthorization(String realm, String user, String passwd) {
        AuthorizationInfo.addDigestAuthorization(Host, Port, realm, user, passwd, getContext());
    }

    /**
     * Adds an authorization entry for the "basic" authorization scheme to the
     * list. If an entry already exists for the "basic" scheme and the specified
     * realm then it is overwritten.
     * <p/>
     * This is a convenience method and just invokes the corresponding method in
     * AuthorizationInfo.
     *
     * @param realm
     *         the realm
     * @param user
     *         the username
     * @param passw
     *         the password
     * @see AuthorizationInfo#addBasicAuthorization(java.lang.String, int,
     *      java.lang.String, java.lang.String, java.lang.String)
     */
    public void addBasicAuthorization(String realm, String user, String passwd) {
        AuthorizationInfo.addBasicAuthorization(Host, Port, realm, user, passwd, getContext());
    }

    /**
     * Sets the default proxy server to use. The proxy will only be used for new
     * <var>HTTPConnection</var>s created after this call and will not affect
     * currrent instances of <var>HTTPConnection</var>. A null or empty string
     * <var>host</var> parameter disables the proxy.
     * <p/>
     * In an application or using the Appletviewer an alternative to this method
     * is to set the following properties (either in the properties file or on
     * the command line): <var>http.proxyHost</var> and
     * <var>http.proxyPort</var>. Whether <var>http.proxyHost</var> is set or not
     * determines whether a proxy server is used.
     * <p/>
     * If the proxy server requires authorization and you wish to set this
     * authorization information in the code, then you may use any of the
     * <var>AuthorizationInfo.addXXXAuthorization()</var> methods to do so.
     * Specify the same <var>host</var> and <var>port</var> as in this method. If
     * you have not given any authorization info and the proxy server requires
     * authorization then you will be prompted for the necessary info via a popup
     * the first time you do a request.
     *
     * @param host
     *         the host on which the proxy server resides.
     * @param port
     *         the port the proxy server is listening on.
     * @see #setCurrentProxy(java.lang.String, int)
     */
    public static void setProxyServer(String host, int port) {
        if (host == null || host.trim().length() == 0)
            Default_Proxy_Host = null;
        else {
            Default_Proxy_Host = host.trim().toLowerCase();
            Default_Proxy_Port = port;
        }
    }

    /**
     * Sets the proxy used by this instance. This can be used to override the
     * proxy setting inherited from the default proxy setting. A null or empty
     * string <var>host</var> parameter disables the proxy.
     * <p/>
     * Note that if you set a proxy for the connection using this method, and a
     * request made over this connection is redirected to a different server,
     * then the connection used for new server will <em>not</em> pick this proxy
     * setting, but instead will use the default proxy settings.
     *
     * @param host
     *         the host the proxy runs on
     * @param port
     *         the port the proxy is listening on
     * @see #setProxyServer(java.lang.String, int)
     */
    public synchronized void setCurrentProxy(String host, int port) {
        if (host == null || host.trim().length() == 0)
            Proxy_Host = null;
        else {
            Proxy_Host = host.trim().toLowerCase();
            if (port <= 0)
                Proxy_Port = 80;
            else
                Proxy_Port = port;
        }

        // the proxy might be talking a different version, so renegotiate
        switch (Protocol) {
            case HTTP:
            case HTTPS:
                if (force_1_0) {
                    ServerProtocolVersion = HTTP_1_0;
                    ServProtVersKnown = true;
                    RequestProtocolVersion = "HTTP/1.0";
                } else {
                    ServerProtocolVersion = HTTP_1_1;
                    ServProtVersKnown = false;
                    RequestProtocolVersion = "HTTP/1.1";
                }
                break;
            case HTTP_NG:
                ServerProtocolVersion = -1; /* Unknown */
                ServProtVersKnown = false;
                RequestProtocolVersion = "";
                break;
            case SHTTP:
                ServerProtocolVersion = -1; /* Unknown */
                ServProtVersKnown = false;
                RequestProtocolVersion = "Secure-HTTP/1.3";
                break;
            default:
                throw new Error("HTTPClient Internal Error: invalid protocol " + Protocol);
        }

        keepAliveUnknown = true;
        doesKeepAlive = false;

        input_demux = null;
        early_stall = null;
        late_stall = null;
        prev_resp = null;
    }

    /**
     * Add <var>host</var> to the list of hosts which should be accessed
     * directly, not via any proxy set by <code>setProxyServer()</code>.
     * <p/>
     * The <var>host</var> may be any of:
     * <UL>
     * <LI>a complete host name (e.g. "www.disney.com")
     * <LI>a domain name; domain names must begin with a dot (e.g. ".disney.com")
     * <LI>an IP-address (e.g. "12.34.56.78")
     * <LI>an IP-subnet, specified as an IP-address and a netmask separated by a
     * "/" (e.g. "34.56.78/255.255.255.192"); a 0 bit in the netmask means that
     * that bit won't be used in the comparison (i.e. the addresses are AND'ed
     * with the netmask before comparison).
     * </UL>
     * <p/>
     * The two properties <var>HTTPClient.nonProxyHosts</var> and
     * <var>http.nonProxyHosts</var> are used when this class is loaded to
     * initialize the list of non-proxy hosts. The second property is only read
     * if the first one is not set; the second property is also used the JDK's
     * URLConnection. These properties must contain a "|" separated list of
     * entries which conform to the above rules for the <var>host</var> parameter
     * (e.g. "11.22.33.44|.disney.com").
     *
     * @param host
     *         a host name, domain name, IP-address or IP-subnet.
     * @throws ParseException
     *         if the length of the netmask does not match the
     *         length of the IP-address
     */
    public static void dontProxyFor(String host) throws ParseException {
        host = host.trim().toLowerCase();

        // check for domain name

        if (host.charAt(0) == '.') {
            if (!non_proxy_dom_list.contains(host))
                non_proxy_dom_list.addElement(host);
            return;
        }

        // check for host name

        for (int idx = 0; idx < host.length(); idx++) {
            if (!Character.isDigit(host.charAt(idx)) && host.charAt(idx) != '.' && host.charAt(idx) != '/') {
                non_proxy_host_list.put(host, "");
                return;
            }
        }

        // must be an IP-address

        byte[] ip_addr;
        byte[] ip_mask;
        int slash;
        if ((slash = host.indexOf('/')) != -1) // IP subnet
        {
            ip_addr = string2arr(host.substring(0, slash));
            ip_mask = string2arr(host.substring(slash + 1));
            if (ip_addr.length != ip_mask.length)
                throw new ParseException("length of IP-address (" + ip_addr.length + ") != length of netmask ("
                                         + ip_mask.length + ")");
        } else {
            ip_addr = string2arr(host);
            ip_mask = new byte[ip_addr.length];
            for (int idx = 0; idx < ip_mask.length; idx++)
                ip_mask[idx] = (byte)255;
        }

        // check if addr or subnet already exists

        ip_loop:
        for (int idx = 0; idx < non_proxy_addr_list.size(); idx++) {
            byte[] addr = (byte[])non_proxy_addr_list.elementAt(idx);
            byte[] mask = (byte[])non_proxy_mask_list.elementAt(idx);
            if (addr.length != ip_addr.length)
                continue;

            for (int idx2 = 0; idx2 < addr.length; idx2++) {
                if ((ip_addr[idx2] & mask[idx2]) != (addr[idx2] & mask[idx2]) || (mask[idx2] != ip_mask[idx2]))
                    continue ip_loop;
            }

            return; // already exists
        }
        non_proxy_addr_list.addElement(ip_addr);
        non_proxy_mask_list.addElement(ip_mask);
    }

    /**
     * Convenience method to add a number of hosts at once. If any one host is
     * null or cannot be parsed it is ignored.
     *
     * @param hosts
     *         The list of hosts to set
     * @see #dontProxyFor(java.lang.String)
     * @since V0.3-2
     */
    public static void dontProxyFor(String[] hosts) {
        if (hosts == null || hosts.length == 0)
            return;

        for (int idx = 0; idx < hosts.length; idx++) {
            try {
                if (hosts[idx] != null)
                    dontProxyFor(hosts[idx]);
            } catch (ParseException pe) {
                // ignore it
            }
        }
    }

    /**
     * Remove <var>host</var> from the list of hosts for which the proxy should
     * not be used. This modifies the same list that <code>dontProxyFor()</code>
     * uses, i.e. this is used to undo a <code>dontProxyFor()</code> setting. The
     * syntax for <var>host</var> is specified in <code>dontProxyFor()</code>.
     *
     * @param host
     *         a host name, domain name, IP-address or IP-subnet.
     * @return true if the remove was sucessful, false otherwise
     * @throws ParseException
     *         if the length of the netmask does not match the
     *         length of the IP-address
     * @see #dontProxyFor(java.lang.String)
     */
    public static boolean doProxyFor(String host) throws ParseException {
        host = host.trim().toLowerCase();

        // check for domain name

        if (host.charAt(0) == '.')
            return non_proxy_dom_list.removeElement(host);

        // check for host name

        for (int idx = 0; idx < host.length(); idx++) {
            if (!Character.isDigit(host.charAt(idx)) && host.charAt(idx) != '.' && host.charAt(idx) != '/')
                return (non_proxy_host_list.remove(host) != null);
        }

        // must be an IP-address

        byte[] ip_addr;
        byte[] ip_mask;
        int slash;
        if ((slash = host.indexOf('/')) != -1) // IP subnet
        {
            ip_addr = string2arr(host.substring(0, slash));
            ip_mask = string2arr(host.substring(slash + 1));
            if (ip_addr.length != ip_mask.length)
                throw new ParseException("length of IP-address (" + ip_addr.length + ") != length of netmask ("
                                         + ip_mask.length + ")");
        } else {
            ip_addr = string2arr(host);
            ip_mask = new byte[ip_addr.length];
            for (int idx = 0; idx < ip_mask.length; idx++)
                ip_mask[idx] = (byte)255;
        }

        ip_loop:
        for (int idx = 0; idx < non_proxy_addr_list.size(); idx++) {
            byte[] addr = (byte[])non_proxy_addr_list.elementAt(idx);
            byte[] mask = (byte[])non_proxy_mask_list.elementAt(idx);
            if (addr.length != ip_addr.length)
                continue;

            for (int idx2 = 0; idx2 < addr.length; idx2++) {
                if ((ip_addr[idx2] & mask[idx2]) != (addr[idx2] & mask[idx2]) || (mask[idx2] != ip_mask[idx2]))
                    continue ip_loop;
            }

            non_proxy_addr_list.removeElementAt(idx);
            non_proxy_mask_list.removeElementAt(idx);
            return true;
        }
        return false;
    }

    /**
     * Turn an IP-address string into an array (e.g. "12.34.56.78" into { 12, 34,
     * 56, 78 }).
     *
     * @param ip
     *         IP-address
     * @return IP-address in network byte order
     */
    private static byte[] string2arr(String ip) {
        byte[] arr;
        char[] ip_char = new char[ip.length()];
        ip.getChars(0, ip_char.length, ip_char, 0);

        int cnt = 0;
        for (int idx = 0; idx < ip_char.length; idx++)
            if (ip_char[idx] == '.')
                cnt++;
        arr = new byte[cnt + 1];

        cnt = 0;
        int pos = 0;
        for (int idx = 0; idx < ip_char.length; idx++)
            if (ip_char[idx] == '.') {
                arr[cnt] = (byte)Integer.parseInt(ip.substring(pos, idx));
                cnt++;
                pos = idx + 1;
            }
        arr[cnt] = (byte)Integer.parseInt(ip.substring(pos));

        return arr;
    }

    /**
     * Sets the SOCKS server to use. The server will only be used for new
     * HTTPConnections created after this call and will not affect currrent
     * instances of HTTPConnection. A null or empty string host parameter
     * disables SOCKS.
     * <p/>
     * The code will try to determine the SOCKS version to use at connection
     * time. This might fail for a number of reasons, however, in which case you
     * must specify the version explicitly.
     *
     * @param host
     *         the host on which the proxy server resides. The port used is
     *         the default port 1080.
     * @see #setSocksServer(java.lang.String, int, int)
     */
    public static void setSocksServer(String host) {
        setSocksServer(host, 1080);
    }

    /**
     * Sets the SOCKS server to use. The server will only be used for new
     * HTTPConnections created after this call and will not affect currrent
     * instances of HTTPConnection. A null or empty string host parameter
     * disables SOCKS.
     * <p/>
     * The code will try to determine the SOCKS version to use at connection
     * time. This might fail for a number of reasons, however, in which case you
     * must specify the version explicitly.
     *
     * @param host
     *         the host on which the proxy server resides.
     * @param port
     *         the port the proxy server is listening on.
     * @see #setSocksServer(java.lang.String, int, int)
     */
    public static void setSocksServer(String host, int port) {
        if (port <= 0)
            port = 1080;

        if (host == null || host.length() == 0)
            Default_Socks_client = null;
        else
            Default_Socks_client = new SocksClient(host, port);
    }

    /**
     * Sets the SOCKS server to use. The server will only be used for new
     * HTTPConnections created after this call and will not affect currrent
     * instances of HTTPConnection. A null or empty string host parameter
     * disables SOCKS.
     * <p/>
     * In an application or using the Appletviewer an alternative to this method
     * is to set the following properties (either in the properties file or on
     * the command line): <var>HTTPClient.socksHost</var>,
     * <var>HTTPClient.socksPort</var> and <var>HTTPClient.socksVersion</var>.
     * Whether <var>HTTPClient.socksHost</var> is set or not determines whether a
     * SOCKS server is used; if <var>HTTPClient.socksPort</var> is not set it
     * defaults to 1080; if <var>HTTPClient.socksVersion</var> is not set an
     * attempt will be made to automatically determine the version used by the
     * server.
     * <p/>
     * Note: If you have also set a proxy server then a connection will be made
     * to the SOCKS server, which in turn then makes a connection to the proxy
     * server (possibly via other SOCKS servers), which in turn makes the final
     * connection.
     * <p/>
     * If the proxy server is running SOCKS version 5 and requires
     * username/password authorization, and you wish to set this authorization
     * information in the code, then you may use the
     * <var>AuthorizationInfo.addAuthorization()</var> method to do so. Specify
     * the same <var>host</var> and <var>port</var> as in this method, give the
     * <var>scheme</var> "SOCKS5" and the <var>realm</var> "USER/PASS", set the
     * <var>cookie</var> to null and the <var>params</var> to an array containing
     * a single <var>NVPair</var> in turn containing the username and password.
     * Example:
     * <p/>
     * <PRE>
     * NVPair[] up = {new NVPair(username, password)};
     * AuthorizationInfo.addAuthorization(host, port, &quot;SOCKS5&quot;, &quot;USER/PASS&quot;, null, up);
     * </PRE>
     * <p/>
     * If you have not given any authorization info and the proxy server requires
     * authorization then you will be prompted for the necessary info via a popup
     * the first time you do a request.
     *
     * @param host
     *         the host on which the proxy server resides.
     * @param port
     *         the port the proxy server is listening on.
     * @param version
     *         the SOCKS version the server is running. Currently this
     *         must be '4' or '5'.
     * @throws SocksException
     *         If <var>version</var> is not '4' or '5'.
     */
    public static void setSocksServer(String host, int port, int version) throws SocksException {
        if (port <= 0)
            port = 1080;

        if (host == null || host.length() == 0)
            Default_Socks_client = null;
        else
            Default_Socks_client = new SocksClient(host, port, version);
    }

    /**
     * Removes the #... part. Returns the stripped name, or "" if either the
     * <var>file</var> is null or is the empty string (after stripping).
     *
     * @param file
     *         the name to strip
     * @return the stripped name
     */
    private final String stripRef(String file) {
        if (file == null)
            return "";

        int hash = file.indexOf('#');
        if (hash != -1)
            file = file.substring(0, hash);

        return file.trim();
    }

    // private helper methods

    /**
     * Sets up the request, creating the list of headers to send and creating
     * instances of the modules. This may be invoked by subclasses which add
     * further methods (such as those from DAV and IPP).
     *
     * @param method
     *         GET, POST, etc.
     * @param resource
     *         the resource
     * @param headers
     *         an array of headers to be used
     * @param entity
     *         the entity (or null)
     * @param stream
     *         the output stream (or null) - only one of stream and entity
     *         may be non-null
     * @return the response.
     * @throws java.io.IOException
     *         when an exception is returned from the
     *         socket.
     * @throws ModuleException
     *         if an exception is encountered in any module.
     */
    protected final HTTPResponse setupRequest(String method, String resource, NVPair[] headers, byte[] entity,
                                              HttpOutputStream stream) throws IOException, ModuleException {
        Request req = new Request(this, method, resource, mergedHeaders(headers), entity, stream, allowUI);
        RequestList.addToEnd(req);

        try {
            HTTPResponse resp = new HTTPResponse(gen_mod_insts(), Timeout, req);
            handleRequest(req, resp, null, true);
            return resp;
        } finally {
            RequestList.remove(req);
        }
    }

    /**
     * This merges built-in default headers, user-specified default headers, and
     * method-specified headers. Method-specified take precedence over user
     * defaults, which take precedence over built-in defaults. The following
     * headers are removed if found: "Content-length".
     *
     * @param spec
     *         the headers specified in the call to the method
     * @return an array consisting of merged headers.
     */
    private NVPair[] mergedHeaders(NVPair[] spec) {
        int spec_len = (spec != null ? spec.length : 0), defs_len;
        NVPair[] merged;

        synchronized (DefaultHeaders) {
            defs_len = (DefaultHeaders != null ? DefaultHeaders.length : 0);
            merged = new NVPair[spec_len + defs_len];

            // copy default headers
            System.arraycopy(DefaultHeaders, 0, merged, 0, defs_len);
        }

        // merge in selected headers
        int sidx, didx = defs_len;
        for (sidx = 0; sidx < spec_len; sidx++) {
            if (spec[sidx] == null)
                continue;

            String s_name = spec[sidx].getName().trim();
            if (s_name.equalsIgnoreCase("Content-length"))
                continue;

            int search;
            for (search = 0; search < didx; search++) {
                if (merged[search].getName().trim().equalsIgnoreCase(s_name))
                    break;
            }

            merged[search] = spec[sidx];
            if (search == didx)
                didx++;
        }

        if (didx < merged.length)
            merged = Util.resizeArray(merged, didx);

        return merged;
    }

    /** Generate an array of instances of the current modules. */
    private HTTPClientModule[] gen_mod_insts() {
        synchronized (ModuleList) {
            HTTPClientModule[] mod_insts = new HTTPClientModule[ModuleList.size()];

            for (int idx = 0; idx < ModuleList.size(); idx++) {
                Class mod = (Class)ModuleList.elementAt(idx);
                try {
                    mod_insts[idx] = (HTTPClientModule)mod.newInstance();
                } catch (Exception e) {
                    throw new Error("HTTPClient Internal Error: could not " + "create instance of " + mod.getName() + " -\n"
                                    + e);
                }
            }

            return mod_insts;
        }
    }

    /**
     * handles the Request. First the request handler for each module is is
     * invoked, and then if no response was generated the request is sent.
     *
     * @param req
     *         the Request
     * @param http_resp
     *         the HTTPResponse
     * @param resp
     *         the Response
     * @param usemodules
     *         if false then skip module loop
     * @throws IOException
     *         if any module or sendRequest throws it
     * @throws ModuleException
     *         if any module throws it
     */
    void handleRequest(Request req, HTTPResponse http_resp, Response resp, boolean usemodules) throws IOException,
                                                                                                      ModuleException {
        Response[] rsp_arr = {resp};
        HTTPClientModule[] modules = http_resp.getModules();

        // invoke requestHandler for each module

        if (usemodules)
            doModules:for (int idx = 0; idx < modules.length; idx++) {
                int sts = modules[idx].requestHandler(req, rsp_arr);
                switch (sts) {
                    case REQ_CONTINUE: // continue processing
                        break;

                    case REQ_RESTART: // restart processing with first module
                        idx = -1;
                        continue doModules;

                    case REQ_SHORTCIRC: // stop processing and send
                        break doModules;

                    case REQ_RESPONSE: // go to phase 2
                    case REQ_RETURN: // return response immediately
                        if (rsp_arr[0] == null)
                            throw new Error("HTTPClient Internal Error: no " + "response returned by module "
                                            + modules[idx].getClass().getName());
                        http_resp.set(req, rsp_arr[0]);
                        if (req.getStream() != null)
                            req.getStream().ignoreData(req);
                        if (req.internal_subrequest)
                            return;
                        if (sts == REQ_RESPONSE)
                            http_resp.handleResponse();
                        else
                            http_resp.init(rsp_arr[0]);
                        return;

                    case REQ_NEWCON_RST: // new connection
                        if (req.internal_subrequest)
                            return;
                        req.getConnection().handleRequest(req, http_resp, rsp_arr[0], true);
                        return;

                    case REQ_NEWCON_SND: // new connection, send immediately
                        if (req.internal_subrequest)
                            return;
                        req.getConnection().handleRequest(req, http_resp, rsp_arr[0], false);
                        return;

                    default: // not valid
                        throw new Error("HTTPClient Internal Error: invalid status" + " " + sts + " returned by module "
                                        + modules[idx].getClass().getName());
                }
            }

        if (req.internal_subrequest)
            return;

        // Send the request across the wire

        if (req.getStream() != null && req.getStream().getLength() == -1) {
            if (!ServProtVersKnown || ServerProtocolVersion < HTTP_1_1 || no_chunked) {
                req.getStream().goAhead(req, null, http_resp.getTimeout());
                http_resp.set(req, req.getStream());
            } else {
                // add Transfer-Encoding header if necessary
                int idx;
                NVPair[] hdrs = req.getHeaders();
                for (idx = 0; idx < hdrs.length; idx++)
                    if (hdrs[idx].getName().equalsIgnoreCase("Transfer-Encoding"))
                        break;

                if (idx == hdrs.length) {
                    hdrs = Util.resizeArray(hdrs, idx + 1);
                    hdrs[idx] = new NVPair("Transfer-Encoding", "chunked");
                    req.setHeaders(hdrs);
                } else {
                    String v = hdrs[idx].getValue();
                    try {
                        if (!Util.hasToken(v, "chunked"))
                            hdrs[idx] = new NVPair("Transfer-Encoding", v + ", chunked");
                    } catch (ParseException pe) {
                        throw new IOException(pe.toString());
                    }
                }

                http_resp.set(req, sendRequest(req, http_resp.getTimeout()));
            }
        } else
            http_resp.set(req, sendRequest(req, http_resp.getTimeout()));

        if (req.aborted)
            throw new IOException("Request aborted by user");
    }

    /** These mark the response to stall the next request on, if any */
    private volatile Response early_stall = null;

    private volatile Response late_stall = null;

    private volatile Response prev_resp = null;

    /** This marks the socket output stream as still being used */
    private boolean output_finished = true;

    /**
     * sends the request over the line.
     *
     * @param req
     *         the request
     * @param con_timeout
     *         the timeout to use when establishing a socket
     *         connection; an InterruptedIOException is thrown if the procedure
     *         times out.
     * @param http_resp
     *         the HTTPResponse to add the new response to
     * @throws IOException
     *         if thrown by the socket
     * @throws InterruptedIOException
     *         if the connection is not established
     *         within the specified timeout
     * @throws ModuleException
     *         if any module throws it during the SSL-
     *         tunneling handshake
     */
    Response sendRequest(Request req, int con_timeout) throws IOException, ModuleException {
        ByteArrayOutputStream hdr_buf = new ByteArrayOutputStream(600);
        Response resp = null;
        boolean keep_alive;

        // The very first request is special in that we need its response
        // before any further requests may be made. This is to set things
        // like the server version.

        if (early_stall != null) {
            try {
                if (log.isDebugEnabled())
                    log.debug("Early-stalling Request: " + req.getMethod() + " " + req.getRequestURI());

                synchronized (early_stall) {
                    // wait till the response is received
                    try {
                        early_stall.getVersion();
                    } catch (IOException ioe) {
                    }
                    early_stall = null;
                }
            } catch (NullPointerException npe) {
            }
        }

        String[] con_hdrs = assembleHeaders(req, hdr_buf);

        // determine if the connection should be kept alive after this
        // request

        try {
            if (ServerProtocolVersion >= HTTP_1_1 && !Util.hasToken(con_hdrs[0], "close")
                || ServerProtocolVersion == HTTP_1_0 && Util.hasToken(con_hdrs[0], "keep-alive"))
                keep_alive = true;
            else
                keep_alive = false;
        } catch (ParseException pe) {
            throw new IOException(pe.toString());
        }

        synchronized (this) {
            // Sometimes we must stall the pipeline until the previous request
            // has been answered. However, if we are going to open up a new
            // connection anyway we don't really need to stall.

            if (late_stall != null) {
                if (input_demux != null || keepAliveUnknown) {
                    if (log.isDebugEnabled())
                        log.debug("Stalling Request: " + req.getMethod() + " " + req.getRequestURI());

                    try
                    // wait till the response is received
                    {
                        late_stall.getVersion();
                        if (keepAliveUnknown)
                            determineKeepAlive(late_stall);
                    } catch (IOException ioe) {
                    }
                }

                late_stall = null;
            }

         /*
          * POSTs must not be pipelined because of problems if the connection is
          * aborted. Since it is generally impossible to know what urls POST will
          * influence it is impossible to determine if a sequence of requests
          * containing a POST is idempotent. Also, for retried requests we don't
          * want to pipeline either.
          */
            if ((req.getMethod().equals("POST") || req.dont_pipeline) && prev_resp != null && input_demux != null) {

                if (log.isDebugEnabled())
                    log.debug("Stalling Request: " + req.getMethod() + " " + req.getRequestURI());

                try
                // wait till the response is received
                {
                    prev_resp.getVersion();
                } catch (IOException ioe) {
                }
            }

            // If the previous request used an output stream, then wait till
            // all the data has been written

            if (!output_finished) {
                try {
                    wait();
                } catch (InterruptedException ie) {
                    throw new IOException(ie.toString());
                }
            }

            if (req.aborted)
                throw new IOException("Request aborted by user");

            int try_count = 3;
         /*
          * what a hack! This is to handle the case where the server closes the
          * connection but we don't realize it until we try to send something. The
          * problem is that we only get IOException, but we need a finer
          * specification (i.e. whether it's an EPIPE or something else); I don't
          * trust relying on the message part of IOException (which on
          * SunOS/Solaris gives 'Broken pipe', but what on Windoze/Mac?).
          */

            while (try_count-- > 0) {
                try {
                    // get a client socket

                    Socket sock;
                    if (input_demux == null || (sock = input_demux.getSocket()) == null) {
                        sock = getSocket(con_timeout);

                        if (Protocol == HTTPS) {
                            if (Proxy_Host != null) {
                                Socket[] sarr = {sock};
                                resp = enableSSLTunneling(sarr, req, con_timeout);
                                if (resp != null) {
                                    resp.final_resp = true;
                                    return resp;
                                }
                                sock = sarr[0];
                            }

                            sock.setSoTimeout(con_timeout);
                            // sock = new SSLSocket(sock);
                        }

                        input_demux = new StreamDemultiplexor(Protocol, sock, this);
                        DemuxList.addToEnd(input_demux);
                        keepAliveReqLeft = keepAliveReqMax;
                    }

                    if (req.aborted)
                        throw new IOException("Request aborted by user");

                    if (log.isDebugEnabled())
                        log.debug("Sending Request");

                    // Send headers

                    OutputStream sock_out = sock.getOutputStream();
                    if (haveMSLargeWritesBug)
                        sock_out = new MSLargeWritesBugStream(sock_out);

                    hdr_buf.writeTo(sock_out);

                    // Wait for "100 Continue" status if necessary

                    try {
                        if (ServProtVersKnown && ServerProtocolVersion >= HTTP_1_1
                            && Util.hasToken(con_hdrs[1], "100-continue")) {
                            resp = new Response(req, (Proxy_Host != null && Protocol != HTTPS), input_demux);
                            resp.timeout = 60;
                            if (resp.getContinue() != 100)
                                break;
                        }
                    } catch (ParseException pe) {
                        throw new IOException(pe.toString());
                    } catch (InterruptedIOException iioe) {
                    } finally {
                        if (resp != null)
                            resp.timeout = 0;
                    }

                    // POST/PUT data

                    if (req.getData() != null && req.getData().length > 0) {
                        if (req.delay_entity > 0) {
                            // wait for something on the network; check available()
                            // roughly every 100 ms

                            long num_units = req.delay_entity / 100;
                            long one_unit = req.delay_entity / num_units;

                            for (int idx = 0; idx < num_units; idx++) {
                                if (input_demux.available(null) != 0)
                                    break;
                                try {
                                    Thread.sleep(one_unit);
                                } catch (InterruptedException ie) {
                                }
                            }

                            if (input_demux.available(null) == 0)
                                sock_out.write(req.getData()); // he's still waiting
                            else
                                keep_alive = false; // Uh oh!
                        } else
                            sock_out.write(req.getData());
                    }

                    if (req.getStream() != null)
                        req.getStream().goAhead(req, sock_out, 0);
                    else
                        sock_out.flush();

                    // get a new response.
                    // Note: this does not do a read on the socket.

                    if (resp == null)
                        resp = new Response(req, (Proxy_Host != null && Protocol != HTTPS), input_demux);
                } catch (IOException ioe) {

                    log.error("Send request error", ioe);

                    closeDemux(ioe, true);

                    if (try_count == 0 || ioe instanceof UnknownHostException || ioe instanceof ConnectException
                        || ioe instanceof NoRouteToHostException || ioe instanceof InterruptedIOException || req.aborted)
                        throw ioe;

                    log.info("Retrying request");
                    continue;
                }

                break;
            }

            prev_resp = resp;

            // close the stream after this response if necessary

            if ((!keepAliveUnknown && !doesKeepAlive) || !keep_alive || (keepAliveReqMax != -1 && keepAliveReqLeft-- == 0)) {
                input_demux.markForClose(resp);
                input_demux = null;
            } else
                input_demux.restartTimer();

            if (keepAliveReqMax != -1)

                if (log.isDebugEnabled())
                    log.debug("Number of requests left: " + keepAliveReqLeft);

         /*
          * We don't pipeline the first request, as we need some info about the
          * server (such as which http version it complies with)
          */
            if (!ServProtVersKnown) {
                early_stall = resp;
                resp.markAsFirstResponse(req);
            }

         /*
          * Also don't pipeline until we know if the server supports keep-alive's
          * or not. Note: strictly speaking, HTTP/1.0 keep-alives don't mean we can
          * pipeline requests. I seem to remember some (beta?) version of
          * Netscape's Enterprise server which barfed if you tried push requests
          * down it's throat w/o waiting for the previous response first. However,
          * I've not been able to find such a server lately, and so I'm taking the
          * risk and assuming we can in fact pipeline requests to HTTP/1.0 servers.
          */
            if (keepAliveUnknown ||
                // We don't pipeline POST's ...
                !IdempotentSequence.methodIsIdempotent(req.getMethod()) || req.dont_pipeline || // Retries
                // disable
                // pipelining
                // too
                neverPipeline) // Emergency measure: prevent all pipelining
            {
                late_stall = resp;
            }

         /*
          * If there is an output stream then just tell the other threads to wait;
          * the stream will notify() when it's done. If there isn't any stream then
          * wake up a waiting thread (if any).
          */
            if (req.getStream() != null)
                output_finished = false;
            else {
                output_finished = true;
                notify();
            }

            // Looks like were finally done
            if (log.isDebugEnabled())
                log.debug("Request sent");
        }

        return resp;
    }

    /**
     * Gets a socket. Creates a socket to the proxy if set, or else to the actual
     * destination.
     *
     * @param con_timeout
     *         if not 0 then start a new thread to establish the the
     *         connection and join(con_timeout) it. If the join() times out an
     *         InteruptedIOException is thrown.
     */
    private Socket getSocket(int con_timeout) throws IOException {
        Socket sock = null;

        String actual_host;
        int actual_port;

        if (Proxy_Host != null) {
            actual_host = Proxy_Host;
            actual_port = Proxy_Port;
        } else {
            actual_host = Host;
            actual_port = Port;
        }

        if (log.isDebugEnabled())
            log.debug("Creating Socket: " + actual_host + ":" + actual_port);

        if (con_timeout == 0) // normal connection establishment
        {
            if (Socks_client != null)
                sock = Socks_client.getSocket(actual_host, actual_port);
            else {
                // try all A records
                InetAddress[] addr_list = InetAddress.getAllByName(actual_host);
                for (int idx = 0; idx < addr_list.length; idx++) {
                    try {
                        if (LocalAddr == null)
                            sock = new Socket(addr_list[idx], actual_port);
                        else
                            sock = new Socket(addr_list[idx], actual_port, LocalAddr, LocalPort);
                        break; // success
                    } catch (SocketException se) {
                        if (idx == addr_list.length - 1)
                            throw se; // we tried them all
                    }
                }
            }
        } else {
            EstablishConnection con = new EstablishConnection(actual_host, actual_port, Socks_client);
            con.start();
            try {
                con.join(con_timeout);
            } catch (InterruptedException ie) {
            }

            if (con.getException() != null)
                throw con.getException();
            if ((sock = con.getSocket()) == null) {
                con.forget();
                if ((sock = con.getSocket()) == null)
                    throw new InterruptedIOException("Connection establishment timed out");
            }
        }

        return sock;
    }

    /**
     * Enable SSL Tunneling if we're talking to a proxy. See ietf draft
     * draft-luotonen-ssl-tunneling-03 for more info.
     *
     * @param sock
     *         the socket
     * @param req
     *         the request initiating this connection
     * @param timeout
     *         the timeout
     * @return the proxy's last response if unsuccessful, or null if tunnel
     *         successfuly established
     * @throws IOException
     * @throws ModuleException
     */
    private Response enableSSLTunneling(Socket[] sock, Request req, int timeout) throws IOException, ModuleException {
        // copy User-Agent and Proxy-Auth headers from request

        Vector hdrs = new Vector();
        for (int idx = 0; idx < req.getHeaders().length; idx++) {
            String name = req.getHeaders()[idx].getName();
            if (name.equalsIgnoreCase("User-Agent") || name.equalsIgnoreCase("Proxy-Authorization"))
                hdrs.addElement(req.getHeaders()[idx]);
        }

        // create initial CONNECT subrequest

        NVPair[] h = new NVPair[hdrs.size()];
        hdrs.copyInto(h);
        Request connect = new Request(this, "CONNECT", Host + ":" + Port, h, null, null, req.allowUI());
        connect.internal_subrequest = true;

        ByteArrayOutputStream hdr_buf = new ByteArrayOutputStream(600);
        HTTPResponse r = new HTTPResponse(gen_mod_insts(), timeout, connect);

        // send and handle CONNECT request until successful or tired

        Response resp = null;

        while (true) {
            handleRequest(connect, r, resp, true);

            hdr_buf.reset();
            assembleHeaders(connect, hdr_buf);

            if (log.isDebugEnabled())
                log.debug("Sending SSL-Tunneling Subrequest");

            // send CONNECT

            hdr_buf.writeTo(sock[0].getOutputStream());

            // return if successful

            resp = new Response(connect, sock[0].getInputStream());
            if (resp.getStatusCode() == 200)
                return null;

            // failed!

            // make life easy: read data and close socket

            try {
                resp.getData();
            } catch (IOException ioe) {
            }
            try {
                sock[0].close();
            } catch (IOException ioe) {
            }

            // handle response

            r.set(connect, resp);
            if (!r.handleResponse())
                return resp;

            sock[0] = getSocket(timeout);
        }
    }

    /**
     * This writes out the headers on the <var>hdr_buf</var>. It takes special
     * precautions for the following headers:
     * <DL>
     * <DT>Content-type<DI>This is only written if the request has an entity. If
     * the request has an entity and no content-type header was given for the
     * request it defaults to "application/octet-stream"
     * <DT>
     * Content-length<DI>This header is generated if the request has an entity
     * and the entity isn't being sent with the Transfer-Encoding "chunked".
     * <DT>
     * User-Agent <DI>If not present it will be generated with the current
     * HTTPClient version strings. Otherwise the version string is appended to
     * the given User-Agent string.
     * <DT>Connection <DI>This header is only written if no proxy is used. If no
     * connection header is specified and the server is not known to understand
     * HTTP/1.1 or later then a "Connection: keep-alive" header is generated.
     * <DT>Proxy-Connection<DI>This header is only written if a proxy is used. If
     * no connection header is specified and the proxy is not known to understand
     * HTTP/1.1 or later then a "Proxy-Connection: keep-alive" header is
     * generated.
     * <DT>Keep-Alive <DI>This header is only written if the Connection or
     * Proxy-Connection header contains the Keep-Alive token.
     * <DT>
     * Expect <DI>If there is no entity and this header contains the
     * "100-continue" token then this token is removed. before writing the
     * header.
     * <DT>TE <DI>If this header does not exist, it is created; else if the
     * "trailers" token is not specified this token is added; else the header is
     * not touched.
     * </DL>
     * Furthermore, it escapes various characters in request-URI.
     *
     * @param req
     *         the Request
     * @param hdr_buf
     *         the buffer onto which to write the headers
     * @return an array of headers; the first element contains the the value of
     *         the Connection or Proxy-Connectin header, the second element the
     *         value of the Expect header.
     * @throws IOException
     *         if writing on <var>hdr_buf</var> generates an an
     *         IOException, or if an error occurs during parsing of a header
     */
    private String[] assembleHeaders(Request req, ByteArrayOutputStream hdr_buf) throws IOException {
        DataOutputStream dataout = new DataOutputStream(hdr_buf);
        String[] con_hdrs = {"", ""};
        NVPair[] hdrs = req.getHeaders();

        // remember various headers

        int ho_idx = -1, ct_idx = -1, ua_idx = -1, co_idx = -1, pc_idx = -1, ka_idx = -1, ex_idx = -1, te_idx = -1, tc_idx =
                -1, ug_idx = -1;
        for (int idx = 0; idx < hdrs.length; idx++) {
            String name = hdrs[idx].getName().trim().toLowerCase();
            if (name.equals("host"))
                ho_idx = idx;
            else if (name.equals("content-type"))
                ct_idx = idx;
            else if (name.equals("user-agent"))
                ua_idx = idx;
            else if (name.equals("connection"))
                co_idx = idx;
            else if (name.equals("proxy-connection"))
                pc_idx = idx;
            else if (name.equals("keep-alive"))
                ka_idx = idx;
            else if (name.equals("expect"))
                ex_idx = idx;
            else if (name.equals("te"))
                te_idx = idx;
            else if (name.equals("transfer-encoding"))
                tc_idx = idx;
            else if (name.equals("upgrade"))
                ug_idx = idx;
        }

        // Generate request line and Host header

        String file = Util.escapeUnsafeChars(req.getRequestURI());
        if (Proxy_Host != null && Protocol != HTTPS && !file.equals("*"))
            dataout.writeBytes(req.getMethod() + " http://" + Host + ":" + Port + file + " " + RequestProtocolVersion
                               + "\r\n");
        else
            dataout.writeBytes(req.getMethod() + " " + file + " " + RequestProtocolVersion + "\r\n");

        String h_hdr = (ho_idx >= 0) ? hdrs[ho_idx].getValue().trim() : Host;
        if (Port != URI.defaultPort(getProtocol()))
            dataout.writeBytes("Host: " + h_hdr + ":" + Port + "\r\n");
        else
            // Netscape-Enterprise has some bugs...
            dataout.writeBytes("Host: " + h_hdr + "\r\n");

      /*
       * What follows is the setup for persistent connections. We default to doing
       * persistent connections for both HTTP/1.0 and HTTP/1.1, unless we're using
       * a proxy server and HTTP/1.0 in which case we must make sure we don't do
       * persistence (because of the problem of 1.0 proxies blindly passing the
       * Connection header on). Note: there is a "Proxy-Connection" header for use
       * with proxies. This however is only understood by Netscape and Netapp
       * caches. Furthermore, it suffers from the same problem as the Connection
       * header in HTTP/1.0 except that at least two proxies must be involved. But
       * I've taken the risk now and decided to send the Proxy-Connection header.
       * If I get complaints I'll remove it again. In any case, with this header
       * we can now modify the above to send the Proxy-Connection header whenever
       * we wouldn't send the normal Connection header.
       */

        String co_hdr = null;
        if (!(ServProtVersKnown && ServerProtocolVersion >= HTTP_1_1 && co_idx == -1)) {
            if (co_idx == -1) { // no connection header given by user
                co_hdr = "Keep-Alive";
                con_hdrs[0] = "Keep-Alive";
            } else {
                con_hdrs[0] = hdrs[co_idx].getValue().trim();
                co_hdr = con_hdrs[0];
            }

            try {
                if (ka_idx != -1 && Util.hasToken(con_hdrs[0], "keep-alive"))
                    dataout.writeBytes("Keep-Alive: " + hdrs[ka_idx].getValue().trim() + "\r\n");
            } catch (ParseException pe) {
                throw new IOException(pe.toString());
            }
        }

        if ((Proxy_Host != null && Protocol != HTTPS) && !(ServProtVersKnown && ServerProtocolVersion >= HTTP_1_1)) {
            if (co_hdr != null) {
                dataout.writeBytes("Proxy-Connection: ");
                dataout.writeBytes(co_hdr);
                dataout.writeBytes("\r\n");
                co_hdr = null;
            }
        }

        if (co_hdr != null) {
            try {
                if (!Util.hasToken(co_hdr, "TE"))
                    co_hdr += ", TE";
            } catch (ParseException pe) {
                throw new IOException(pe.toString());
            }
        } else
            co_hdr = "TE";

        if (ug_idx != -1)
            co_hdr += ", Upgrade";

        if (co_hdr != null) {
            dataout.writeBytes("Connection: ");
            dataout.writeBytes(co_hdr);
            dataout.writeBytes("\r\n");
        }

        // handle TE header

        if (te_idx != -1) {
            dataout.writeBytes("TE: ");
            Vector pte;
            try {
                pte = Util.parseHeader(hdrs[te_idx].getValue());
            } catch (ParseException pe) {
                throw new IOException(pe.toString());
            }

            if (!pte.contains(new HttpHeaderElement("trailers")))
                dataout.writeBytes("trailers, ");

            dataout.writeBytes(hdrs[te_idx].getValue().trim() + "\r\n");
        } else
            dataout.writeBytes("TE: trailers\r\n");

        // User-Agent

        if (ua_idx != -1)
            dataout.writeBytes("User-Agent: " + hdrs[ua_idx].getValue().trim() + " " + version + "\r\n");
        else
            dataout.writeBytes("User-Agent: " + version + "\r\n");

        // Write out any headers left

        for (int idx = 0; idx < hdrs.length; idx++) {
            if (idx != ct_idx && idx != ua_idx && idx != co_idx && idx != pc_idx && idx != ka_idx && idx != ex_idx
                && idx != te_idx && idx != ho_idx)
                dataout.writeBytes(hdrs[idx].getName().trim() + ": " + hdrs[idx].getValue().trim() + "\r\n");
        }

        // Handle Content-type, Content-length and Expect headers

        if (req.getData() != null || req.getStream() != null) {
            dataout.writeBytes("Content-type: ");
            if (ct_idx != -1)
                dataout.writeBytes(hdrs[ct_idx].getValue().trim());
            else
                dataout.writeBytes("application/octet-stream");
            dataout.writeBytes("\r\n");

            if (req.getData() != null)
                dataout.writeBytes("Content-length: " + req.getData().length + "\r\n");
            else if (req.getStream().getLength() != -1 && tc_idx == -1)
                dataout.writeBytes("Content-length: " + req.getStream().getLength() + "\r\n");

            if (ex_idx != -1) {
                con_hdrs[1] = hdrs[ex_idx].getValue().trim();
                dataout.writeBytes("Expect: " + con_hdrs[1] + "\r\n");
            }
        } else if (ex_idx != -1) {
            Vector expect_tokens;
            try {
                expect_tokens = Util.parseHeader(hdrs[ex_idx].getValue());
            } catch (ParseException pe) {
                throw new IOException(pe.toString());
            }

            // remove any 100-continue tokens

            HttpHeaderElement cont = new HttpHeaderElement("100-continue");
            while (expect_tokens.removeElement(cont)) ;

            // write out header if any tokens left

            if (!expect_tokens.isEmpty()) {
                con_hdrs[1] = Util.assembleHeader(expect_tokens);
                dataout.writeBytes("Expect: " + con_hdrs[1] + "\r\n");
            }
        }

        dataout.writeBytes("\r\n"); // end of header

        return con_hdrs;
    }

    /**
     * The very first request is special in that we use it to figure out the
     * protocol version the server (or proxy) is compliant with.
     *
     * @return true if all went fine, false if the request needs to be resent
     * @throws IOException
     *         if any exception is thrown by the response
     */
    boolean handleFirstRequest(Request req, Response resp) throws IOException {
        // read response headers to get protocol version used by
        // the server.

        ServerProtocolVersion = String2ProtVers(resp.getVersion());
        ServProtVersKnown = true;

      /*
       * We need to treat connections through proxies specially, because many
       * HTTP/1.0 proxies do not downgrade an HTTP/1.1 response version to
       * HTTP/1.0 (i.e. when we are talking to an HTTP/1.1 server through an
       * HTTP/1.0 proxy we are mislead to thinking we're talking to an HTTP/1.1
       * proxy). We use the absence of the Via header to detect whether we're
       * talking to an HTTP/1.0 proxy, unless the status code indicates an error
       * from the proxy itself. However, this only works when the chain contains
       * only HTTP/1.0 proxies; if you have <client - 1.0 proxy - 1.1 proxy -
       * server> then this will fail too. Unfortunately there seems to be no way
       * to reliably detect broken HTTP/1.0 proxies...
       */
        int sts = resp.getStatusCode();
        if ((Proxy_Host != null && Protocol != HTTPS) && resp.getHeader("Via") == null && sts != 407 && sts != 502
            && sts != 504)
            ServerProtocolVersion = HTTP_1_0;

        //    log.warn("Protocol Version established: " + ProtVers2String(ServerProtocolVersion));

        // some (buggy) servers return an error status if they get a
        // version they don't comprehend

        if (ServerProtocolVersion == HTTP_1_0 && (resp.getStatusCode() == 400 || resp.getStatusCode() == 500)) {
            if (input_demux != null)
                input_demux.markForClose(resp);
            input_demux = null;
            RequestProtocolVersion = "HTTP/1.0";
            return false;
        }

        return true;
    }

    private void determineKeepAlive(Response resp) throws IOException {
        // try and determine if this server does keep-alives

        String con;

        try {
            if (ServerProtocolVersion >= HTTP_1_1
                || ((((Proxy_Host == null || Protocol == HTTPS)
                      && (con = resp.getHeader("Connection")) != null)
                     || ((Proxy_Host != null && Protocol != HTTPS)
                         && (con = resp.getHeader("Proxy-Connection")) != null))
                    && Util.hasToken(con, "keep-alive"))) {
                doesKeepAlive = true;
                keepAliveUnknown = false;
                if (log.isDebugEnabled())
                    log.debug("Keep-Alive enabled");

            } else if (resp.getStatusCode() < 400)
                keepAliveUnknown = false;

            // get maximum number of requests

            if (doesKeepAlive && ServerProtocolVersion == HTTP_1_0 && (con = resp.getHeader("Keep-Alive")) != null) {
                HttpHeaderElement max = Util.getElement(Util.parseHeader(con), "max");
                if (max != null && max.getValue() != null) {
                    keepAliveReqMax = Integer.parseInt(max.getValue());
                    keepAliveReqLeft = keepAliveReqMax;

                    if (log.isDebugEnabled())
                        log.debug("Max Keep-Alive requests: " + keepAliveReqMax);
                }
            }
        } catch (ParseException pe) {
        } catch (NumberFormatException nfe) {
        } catch (ClassCastException cce) {
        }
    }

    synchronized void outputFinished() {
        output_finished = true;
        notify();
    }

    synchronized void closeDemux(IOException ioe, boolean was_reset) {
        if (input_demux != null)
            input_demux.close(ioe, was_reset);

        early_stall = null;
        late_stall = null;
        prev_resp = null;
    }

    final static String ProtVers2String(int prot_vers) {
        return "HTTP/" + (prot_vers >>> 16) + "." + (prot_vers & 0xFFFF);
    }

    final static int String2ProtVers(String prot_vers) {
        String vers = prot_vers.substring(5);
        int dot = vers.indexOf('.');
        return Integer.parseInt(vers.substring(0, dot)) << 16 | Integer.parseInt(vers.substring(dot + 1));
    }

    /**
     * Generates a string of the form protocol://host.domain:port .
     *
     * @return the string
     */
    public String toString() {
        return getProtocol() + "://" + getHost() + (getPort() != URI.defaultPort(getProtocol()) ? ":" + getPort() : "");
    }

    private class EstablishConnection extends Thread {
        String actual_host;

        int actual_port;

        IOException exception;

        Socket sock;

        SocksClient Socks_client;

        boolean close;

        EstablishConnection(String host, int port, SocksClient socks) {
            super("EstablishConnection (" + host + ":" + port + ")");
            try {
                setDaemon(true);
            } catch (SecurityException se) {
            } // Oh well...

            actual_host = host;
            actual_port = port;
            Socks_client = socks;

            exception = null;
            sock = null;
            close = false;
        }

        public void run() {
            try {
                if (Socks_client != null)
                    sock = Socks_client.getSocket(actual_host, actual_port);
                else {
                    // try all A records
                    InetAddress[] addr_list = InetAddress.getAllByName(actual_host);
                    for (int idx = 0; idx < addr_list.length; idx++) {
                        try {
                            if (LocalAddr == null)
                                sock = new Socket(addr_list[idx], actual_port);
                            else
                                sock = new Socket(addr_list[idx], actual_port, LocalAddr, LocalPort);
                            break; // success
                        } catch (SocketException se) {
                            if (idx == addr_list.length - 1 || close)
                                throw se; // we tried them all
                        }
                    }
                }
            } catch (IOException ioe) {
                exception = ioe;
            }

            if (close && sock != null) {
                try {
                    sock.close();
                } catch (IOException ioe) {
                }
                sock = null;
            }
        }

        IOException getException() {
            return exception;
        }

        Socket getSocket() {
            return sock;
        }

        void forget() {
            close = true;
        }
    }

    /**
     * M$ has yet another bug in their WinSock: if you try to write too much data
     * at once it'll hang itself. This filter therefore splits big writes up into
     * multiple writes of at most 20K.
     */
    private class MSLargeWritesBugStream extends FilterOutputStream {
        private final int CHUNK_SIZE = 20000;

        MSLargeWritesBugStream(OutputStream os) {
            super(os);
        }

        public void write(byte[] b, int off, int len) throws IOException {
            while (len > CHUNK_SIZE) {
                out.write(b, off, CHUNK_SIZE);
                off += CHUNK_SIZE;
                len -= CHUNK_SIZE;
            }
            out.write(b, off, len);
        }
    }
}
